All of this looks so good, but I already built my app with TornadoFX. I wonder if there is a migration path or some learnings to read from someone who did it?

IIUC, TornadoFX is a javafx-based framework, right? JavaFX has really good Swing interoperability, and Compose also has really good Swing interoperability, so the workflow we've been recommending has been to use Swing as the glue between the two frameworks. This would allow you to embed Compose in your TornadoFX and also embed TornadoFX in your Compose. I think multiple people in this channel have achieved similar with their javafx applications, although I don't remember their handles offhand. Probably worth just giving it a try and see if you like it. The benefit of interoperability is that you can migrate incrementally, and invest more/less depending on how you end up liking it.

Sounds good, thank you.