Well from the compose part it seems that some parts are still missing such as integration with a ui window for drawing skia(like XLIB), among some other things like locale and charset, but not really a lot of stuff
Skiko on the other hand seems to lack a lot if not all of the linux implementation
For what it would be gained, not really much, just thought it would be very cool
I'm already trying to use as many multiplatform libraries as possible, so thats not reeeealy an issue
The main benefit i guess would be not depending on jvm for deployment (i know it can be achieved with graalvm but thats still also not fully stable afaik, and also has some tradeoffs)