What is the state of Multiplatform currently? Is it worth trying to publish a Multiplatform library now, before KLib comes?

Plenty of libraries already publishing. New klib stuff will presumably simplify things but nothing blocking you from putting something out now.

The biggest problems I see facing Multiplatform at the moment are: • Clash between K/N memory model and multi-threaded coroutines. This is being actively worked on and the situation is improving. • Gradle Composite Builds and Multiplatform currently don't work properly together in IntelliJ IDE's - objects in the dependency source-sets aren't resolved even though they should be. For the workflow I want to adopt, where several multi-platform libaries get developed in parallel, Composite builds are idea, making this a rather annoying problem.