I just played some 30 minutes of Dodonpachi and WOW! The input lag is noticeably lower. It now feels just like Daioujou and Ketsui.
I always thought that it was by design, but it seems not. Only thing is now i have to create all my save games again from scratch, but it will be fun
EDIT:
Ok, so a small but very annoying issue with loading in games with bombs (Dodonpachi). I'm playing FBA on mobile (Retroarch core) and when i load a save-game, i HAVE to use the bomb button as it is the only button that activates the loading,
but the moment it loads, it also activates the bomb in the game, which is a game/score breaking issue
Previously, it was the normal fire button that loaded a save-game and there were no issues.