Here the results of my tests so far:
Dreamcast
- control not working (only left and right direction on left analog stick of my ps3 controller is working)
Master System
- Screen not in centre (moved to the right a bit, so that there is a black bar at the left side)
N64
- when pressing Hotkey + B in non Libretro Emulators (when Emulator is set to either AUTO or MUPEN64PLUS) the system crashes/freezes
- when you change Emulator to Libretro and leave Core at "Auto", the games do not start (you get a black screen and it goes back to ES Menu)
3DS
- no Libretro Citra anymore?
- in standalone Citra the screens are stretched (wrong aspect ratio), no control of lower screen (touchscreen/pointer mode with right analog stick) and no hotkey combos (for fast forward, save/load save states) possible and no bezels
Gamecube
- when using PS3 controller the Gamecube controller buttons B and X button (PS3 controller = square and circle) are mixed up/reversed -> can be solved in dolphin-emu-config, controller settings, but this config-change can not be saved permanently
PS2
- up and down directions of right analog stick on ps3 controller are mixed up/reversed (up = down and down = up) -> can be solved in pcsx2 config, controller settings, but this config-change can not be saved permanently