Thank you for pointing this out, I just bought the ROM yesterday and at first I thought it was a part of the game (or my EverDrive was having a heart attack) until the scrolling would sometimes fix it
I'll be sure to enable this setting and give it a-go again tonight
Are you also using an Analogue NT Mini Noir? If so. and you are running Genesis games, there is a way to get full 6-button controller support by using a SNES controller to NES console adapter and the 8bitdo 2.4Ghz SNES controller. The controller adapter is available at MiSTer Addons if you need one. Please let me know if the fully buffered setting does the trick for you. It really is a good game.
I am using the Mini Nt Noire and I'm using the 8BitDo Pro2 controller (specifically the one with the Famicom color scheme) with the wireless 8BitDo dongle and having a blast and have left the full buffer on and played Lifeforce and Air Fortress and didn't notice any lag so I'm leaving the function on for the time being