Hmm, I'm not seeing either of those issues. I have a 1.5TB library imported and have listened for many hours straight without a crash. Version 0.4.2 was just released today. Maybe give that a shot. https://github.com/ludouzi/fooyin/releases/tag/v0.4.2
Strange that you say this because not much changed in this release. It’s mainly an update to Qt6. No big UI or UX. What specifically feels different from Plasma 5?