I'm using FBN emulator, completely offline mode and without Fightcade logged for playing online.
I'm not using Fighcade itself, I'm using Fightcade's Final Burn Neo emulator core that comes with it in default offline way as a normal user would.
I'm not a expert on anything like this to implement Fightcade features on a frontend to resemble 1Up arcade systems.
I'm only really sad cause it was working before and all of a sudden stopped working for some unknown reason, making my bartop cabinet project to waste

I'm just on the offline features of it, not using the online anywhere. It works quite nice though.
The Fightcade itself mirrors your installed emulator and streams the replay from a fight you had if you access the replay url.
You can record and share on Youtube or elsewhere, no lag involved. OBS would do the trick in high bitrate.
Fightcade Final Burn Neo build also allows scripting, which can implement so many stuff on the emulator itself (You mentioned retro achievements and I know they exist, but didn't delve on it yet), but one of the most interesting implementations I saw using scripts was the possibility of having a training core inside the game's rom, with no extra installation or effort.
You can train and test like if it were a home console version of it.
Other than that, I wish this core would be released in the near future, with no strings attached to Fightcade itself.
A full rom set list can be found on archive.org if that's what you mentioned before.
Have a nice beer time.