I have a working build for kotest-js that allows us to nest tests and use suspendable functions at all layers.
It doesn't use the kotlin test task, and doesn't use mocha. Instead it generates a top level function that is then invoked directly in node. At that point, execution is entirely handed by the regular kotest test engine.
If you want to play around, build this branch locally:
https://github.com/kotest/kotest/pull/4040
Then run this branch (clean, build, kotest)
https://github.com/kotest/kotest-examples-javascript/pull/36
Still a lot of caveats but maybe an interesting direction.