Only AppIndicator and KStatusNotifierItem Support. Mostly because wine apps and games tend to open a floating systray if it isn’t there. Other than that, i’m down to no other extensions. I found that most other stuff i changed/added either sounded nice or looked nice in screenshots but did nothing for me in day to day use. Don’t get me wrong. Blur my Shell, Burn my Windows or Dash to Dock all look great. I just found that, after the initial wow factor, they don’t do much for me. The effect wears of quickly and then i don’t notice wether they are there or not.