Ok, I tried FreeBSD 15.0-ALPHA1 on my minipc:
- wifi is performing fine
- KDE runs fine on X and Wayland
- Media keys are not working but it should not be hard to make them work
- Suspension is not working - as expected
- Alt+Tab isn't working both on X and Wayland
All in all, the experience is ok.
I decided to try the latest GhostBSD: it runs fine, Media keys are working, wifi is fine, alt+tab works. Suspend/Resume isn't working, as expected.
I'm now installing KDE on GhostBSD.