what specifically did you have issues with?

i made a GUI with cljfx which uses JavaFX and I didnt really hit any issues (save for i have one bug on startup that ive had trouble ironing out). The app is snappy and feels as native as anything else

Ended with a very modular functional GUI program

the only thing i wasnt super happy about is that i couldnt package it as a simple .bin/.exe bc the jpackage system forces you into making an installer/application (its been a few years since, so its possible theres a graal native solution now)

i highly recommend cljfx. Its the opposite of clunky