Is there any way from code to detect what architecture the code is running under with multiplatform common? (I.e x32 or x64) Or do I need to lift this out to be detected under each platform?

In Kotlin/Native you can use

Platform

, but I think you can not in common code https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.native/-platform/index.html

Better lift it out then to each platform with expect I guess then