I'm not 100% sure here, but I think ES-DE still relies on having access to all files (External storage permission). Because Google Play does only allow this permission for File managers now, I think that might be one of the roadblockers.
which renders the Setting Button on the tab-bar as a barely tapable micro-button
Ay, that's bad, sorry about that. I'll look into that to have that fixed. Out of curiosity: Is the default orientation setting of the RG Cube Landscape or Portrait?
one could select a Roms Folder and the App will assign the appropriate emulator application
Good idea, thank you! I see that this could work as an Autosetup where it simply assigns the emulator it detects. For Retroarch it will be a bit difficult though, because I can't detect what cores are installed. I wrote it down for future features, but first I'm trying to get rid of issues, supporting more emulators and adding must-have features.
Thank you for trying it! It makes me happy that you like it so far :)
I plan to add a proper GameHub (Lite) support in the next update which hopefully fixes this issue for you. For Moonlight, it seems that I completely missed that there is a standalone App, because I was using Artemis for this myself, sorry. Will add the support in the next update as well.