I tested some games from "samcoupe_flop" in mame.
They work very good on the pi4.
Just typing boot and they will run.
(edit : I added the possibility to install autoboot in systems with extras -> full / semi automatic boot)
Only one thing, the used cursor keys for playing games are :for many games a,s,o,p,space. for some games q,w,space. other games use the normal cursor keys.
So it's advisable to use the game specific runcommand loaders for mame or lr-mess.
That way you can customize the keys used per game.
Here are some pictures of manic and ppersia :