I've had a good experience with JavaFX and I even managed to AOT compile two faily complex applications of mine. My advice would just be to stay away from FXML.

I've had a good experience with JavaFX and I even managed to AOT compile two faily complex applications of mine. My advice would just be to stay away from FXML. Also use jlink to build a stripped down JRE for your application and package it with jpackage.