diff --git a/build.sbt b/build.sbt
index 90d63ab78..e9448bcb4 100644
--- a/build.sbt
+++ b/build.sbt
@@ -98,7 +98,6 @@ def commonBaseSettings: Seq[Setting[_]] = Def.settings(
     (Compile / unmanagedSources / inputFileStamps).dependsOn(Compile / javafmtOnCompile).value,
   Test / unmanagedSources / inputFileStamps :=
     (Test / unmanagedSources / inputFileStamps).dependsOn(Test / javafmtOnCompile).value,
-  crossScalaVersions := List(scala212, scala213),
   Test / publishArtifact := false,
   run / fork := true,
 )
@@ -112,8 +111,11 @@ def commonSettings: Seq[Setting[_]] =
       }
     }
   }
-def utilCommonSettings: Seq[Setting[_]] =
-  baseSettings :+ (crossScalaVersions := (scala212 :: scala213 :: Nil))
+
+def utilCommonSettings: Seq[Setting[_]] = Def.settings(
+  baseSettings,
+  crossScalaVersions := Seq(scala212, scala213, scala3)
+)
 
 def minimalSettings: Seq[Setting[_]] =
   commonSettings ++ customCommands ++
@@ -261,7 +263,7 @@ val collectionProj = (project in file("util-collection"))
   .settings(
     name := "Collections",
     testedBaseSettings,
-    utilCommonSettings,
+    baseSettings,
     libraryDependencies ++= Seq(sjsonNewScalaJson.value),
     libraryDependencies ++= (CrossVersion.partialVersion(scalaVersion.value) match {
       case Some((2, major)) if major <= 12 => Seq()
@@ -308,8 +310,7 @@ val logicProj = (project in file("internal") / "util-logic")
 //   the analysis compiler phases and passed back to sbt.  The API structures are defined in a simple
 //   format from which Java sources are generated by the datatype generator Projproject
 lazy val utilInterface = (project in file("internal") / "util-interface").settings(
-  utilCommonSettings,
-  crossScalaVersions := List(scala212),
+  baseSettings,
   javaOnlySettings,
   crossPaths := false,
   autoScalaLibrary := false,
@@ -334,7 +335,8 @@ lazy val utilPosition = (project in file("internal") / "util-position")
     utilMimaSettings,
   )
 
-lazy val utilCore = project.in(file("internal") / "util-core")
+lazy val utilCore = project
+  .in(file("internal") / "util-core")
   .settings(
     utilCommonSettings,
     name := "Util Core",
@@ -517,7 +519,6 @@ lazy val testingProj = (project in file("testing"))
 lazy val testAgentProj = (project in file("testing") / "agent")
   .settings(
     minimalSettings,
-    crossScalaVersions := Seq(baseScalaVersion),
     crossPaths := false,
     autoScalaLibrary := false,
     Compile / doc / javacOptions := Nil,
@@ -607,7 +608,6 @@ lazy val scriptedSbtReduxProj = (project in file("scripted-sbt-redux"))
   .dependsOn(sbtProj % "compile;test->test", commandProj, utilLogging, utilScripted)
   .settings(
     baseSettings,
-    crossScalaVersions := Seq(baseScalaVersion),
     name := "Scripted sbt Redux",
     libraryDependencies ++= Seq(launcherInterface % "provided"),
     mimaSettings,
@@ -619,7 +619,6 @@ lazy val scriptedSbtOldProj = (project in file("scripted-sbt-old"))
   .dependsOn(scriptedSbtReduxProj)
   .settings(
     baseSettings,
-    crossScalaVersions := Seq(baseScalaVersion),
     name := "Scripted sbt",
     mimaSettings,
     mimaBinaryIssueFilters ++= Seq(
@@ -647,7 +646,6 @@ lazy val dependencyTreeProj = (project in file("dependency-tree"))
   .settings(
     sbtPlugin := true,
     baseSettings,
-    crossScalaVersions := Seq(baseScalaVersion),
     name := "sbt-dependency-tree",
     publishMavenStyle := true,
     // mimaSettings,
@@ -805,7 +803,7 @@ lazy val commandProj = (project in file("main-command"))
 lazy val coreMacrosProj = (project in file("core-macros"))
   .dependsOn(collectionProj)
   .settings(
-    testedBaseSettings :+ (crossScalaVersions := (scala212 :: scala213 :: Nil)),
+    testedBaseSettings,
     name := "Core Macros",
     SettingKey[Boolean]("exportPipelining") := false,
     mimaSettings,
@@ -976,7 +974,6 @@ lazy val sbtProj = (project in file("sbt-app"))
       if (scalaVersion.value == baseScalaVersion) version.value
       else version2_13.value
     },
-    crossScalaVersions := Seq(baseScalaVersion),
     crossPaths := false,
     crossTarget := { target.value / scalaVersion.value },
     javaOptions ++= Seq("-Xdebug", "-Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5005"),
@@ -1002,7 +999,6 @@ lazy val serverTestProj = (project in file("server-test"))
   .dependsOn(sbtProj % "compile->test", scriptedSbtReduxProj % "compile->test")
   .settings(
     testedBaseSettings,
-    crossScalaVersions := Seq(baseScalaVersion),
     bspEnabled := false,
     publish / skip := true,
     // make server tests serial
@@ -1130,8 +1126,7 @@ lazy val sbtBig = (project in file(".big"))
 lazy val lowerUtils = (project in (file("internal") / "lower"))
   .aggregate(lowerUtilProjects.map(p => LocalProject(p.id)): _*)
   .settings(
-    publish / skip := true,
-    crossScalaVersions := Nil,
+    publish / skip := true
   )
 
 lazy val upperModules = (project in (file("internal") / "upper"))
@@ -1140,8 +1135,7 @@ lazy val upperModules = (project in (file("internal") / "upper"))
       diff Seq(bundledLauncherProj)).map(p => LocalProject(p.id)): _*
   )
   .settings(
-    publish / skip := true,
-    crossScalaVersions := Nil,
+    publish / skip := true
   )
 
 lazy val sbtIgnoredProblems = {
@@ -1196,7 +1190,6 @@ lazy val vscodePlugin = (project in file("vscode-sbt-scala"))
   .settings(
     bspEnabled := false,
     crossPaths := false,
-    crossScalaVersions := Seq(baseScalaVersion),
     publish / skip := true,
     Compile / compile := {
       val _ = update.value
@@ -1278,8 +1271,7 @@ def allProjects =
 // These need to be cross published to 2.12 and 2.13 for Zinc
 lazy val lowerUtilProjects =
   Seq(
-    collectionProj,
-    coreMacrosProj,
+    utilCore,
     utilCache,
     utilControl,
     utilInterface,
diff --git a/internal/util-core/src/main/scala-2.13/sbt/internal/util/StringTypeTag.scala b/internal/util-core/src/main/scala-2/sbt/internal/util/appmacro/StringTypeTag.scala
similarity index 91%
rename from internal/util-core/src/main/scala-2.13/sbt/internal/util/StringTypeTag.scala
rename to internal/util-core/src/main/scala-2/sbt/internal/util/appmacro/StringTypeTag.scala
index d9abff119..ee7547ec7 100644
--- a/internal/util-core/src/main/scala-2.13/sbt/internal/util/StringTypeTag.scala
+++ b/internal/util-core/src/main/scala-2/sbt/internal/util/appmacro/StringTypeTag.scala
@@ -6,7 +6,7 @@
  * Licensed under Apache License 2.0 (see LICENSE)
  */
 
-package sbt.internal.util
+package sbt.internal.util.appmacro
 
 import scala.language.experimental.macros
 import scala.reflect.macros.blackbox
@@ -33,6 +33,6 @@ object StringTypeTag {
     }
 
     val key = Literal(Constant(typeToString(tpe)))
-    q"new sbt.internal.util.StringTypeTag[$tpe]($key)"
+    q"new sbt.internal.util.appmacro.StringTypeTag[$tpe]($key)"
   }
 }
diff --git a/internal/util-core/src/main/scala-3/sbt/internal/util/StringTypeTag.scala b/internal/util-core/src/main/scala-3/sbt/internal/util/appmacro/StringTypeTag.scala
similarity index 96%
rename from internal/util-core/src/main/scala-3/sbt/internal/util/StringTypeTag.scala
rename to internal/util-core/src/main/scala-3/sbt/internal/util/appmacro/StringTypeTag.scala
index 4cc8c2981..a144923a9 100644
--- a/internal/util-core/src/main/scala-3/sbt/internal/util/StringTypeTag.scala
+++ b/internal/util-core/src/main/scala-3/sbt/internal/util/appmacro/StringTypeTag.scala
@@ -5,7 +5,7 @@
  * Licensed under Apache License 2.0 (see LICENSE)
  */
 
-package sbt.internal.util
+package sbt.internal.util.appmacro
 
 final class StringTypeTag[A](val key: String):
   override def toString(): String = key
diff --git a/internal/util-logging/src/main/scala/sbt/internal/util/ManagedLogger.scala b/internal/util-logging/src/main/scala/sbt/internal/util/ManagedLogger.scala
index 3c9d90643..e0ca75aed 100644
--- a/internal/util-logging/src/main/scala/sbt/internal/util/ManagedLogger.scala
+++ b/internal/util-logging/src/main/scala/sbt/internal/util/ManagedLogger.scala
@@ -10,7 +10,7 @@ package sbt.internal.util
 import sbt.internal.util.codec.JsonProtocol._
 import sbt.util._
 import sjsonnew.JsonFormat
-import sbt.internal.util.StringTypeTag
+import sbt.internal.util.appmacro.StringTypeTag
 
 private[sbt] trait MiniLogger {
   def log[T](level: Level.Value, message: ObjectEvent[T]): Unit
diff --git a/internal/util-logging/src/main/scala/sbt/util/LogExchange.scala b/internal/util-logging/src/main/scala/sbt/util/LogExchange.scala
index 5d63b2418..7edd4d3ec 100644
--- a/internal/util-logging/src/main/scala/sbt/util/LogExchange.scala
+++ b/internal/util-logging/src/main/scala/sbt/util/LogExchange.scala
@@ -12,7 +12,7 @@ import org.apache.logging.log4j.core.layout.PatternLayout
 import org.apache.logging.log4j.core.{ LoggerContext => XLoggerContext }
 import org.apache.logging.log4j.{ LogManager => XLogManager }
 import sbt.internal.util.{ Appender, ManagedLogger, TraceEvent, SuccessEvent, Util }
-import sbt.internal.util.StringTypeTag
+import sbt.internal.util.appmacro.StringTypeTag
 
 import java.util.concurrent.ConcurrentHashMap
 import scala.collection.concurrent
diff --git a/internal/util-logging/src/test/scala/LogExchangeSpec.scala b/internal/util-logging/src/test/scala/LogExchangeSpec.scala
deleted file mode 100644
index 57dfbe03c..000000000
--- a/internal/util-logging/src/test/scala/LogExchangeSpec.scala
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * sbt
- * Copyright 2011 - 2018, Lightbend, Inc.
- * Copyright 2008 - 2010, Mark Harrah
- * Licensed under Apache License 2.0 (see LICENSE)
- */
-
-package sbt.util
-
-import sbt.internal.util._
-import sbt.internal.util.appmacro.StringTypeTag
-import org.scalatest.flatspec.AnyFlatSpec
-import org.scalatest.matchers.should.Matchers
-
-class LogExchangeSpec extends AnyFlatSpec with Matchers {
-  import LogExchange._
-
-  checkTypeTag("stringTypeTagThrowable", stringTypeTagThrowable, StringTypeTag[Throwable])
-
-  checkTypeTag(
-    "stringTypeTagTraceEvent",
-    stringTypeTagTraceEvent,
-    StringTypeTag[TraceEvent]
-  )
-  checkTypeTag(
-    "stringTypeTagSuccessEvent",
-    stringTypeTagSuccessEvent,
-    StringTypeTag[SuccessEvent]
-  )
-
-  private def checkTypeTag[A](name: String, inc: StringTypeTag[A], exp: StringTypeTag[A]): Unit =
-    s"LogExchange.$name" should s"match real StringTypeTag[$exp]" in {
-      val incomingString = inc.key
-      val expectedString = exp.key
-      if ((incomingString startsWith "scala.") || (expectedString startsWith "scala.")) {
-        // > historically [Scala] has been inconsistent whether `scala.` is included, or not
-        // > would it be hard to make the test accept either result?
-        // https://github.com/scala/community-builds/pull/758#issuecomment-409760633
-        assert((incomingString stripPrefix "scala.") == (expectedString stripPrefix "scala."))
-      } else {
-        assert(incomingString == expectedString)
-      }
-    }
-}
diff --git a/internal/util-logging/src/test/scala/ManagedLoggerSpec.scala b/internal/util-logging/src/test/scala/ManagedLoggerSpec.scala
index b995b8621..4cc44fb29 100644
--- a/internal/util-logging/src/test/scala/ManagedLoggerSpec.scala
+++ b/internal/util-logging/src/test/scala/ManagedLoggerSpec.scala
@@ -92,7 +92,7 @@ class ManagedLoggerSpec extends AnyFlatSpec with Matchers {
     } {
       pool.submit(new Runnable {
         def run(): Unit = {
-          val stringTypeTag = StringTypeTag[List[Int]]
+          val stringTypeTag = implicitly[StringTypeTag[List[Int]]]
           val log = newLogger(s"foo$i")
           context.addAppender(s"foo$i", asyncStdout -> Level.Info)
           if (i % 100 == 0) {