So, you'll need AHK installed if you haven’t already (maybe it can be done ‘natively’ within LB’s emulator ahk settings but I haven’t tried yet).
I've cobbled together a number of pointers I’ve learned along the way for getting the Naomi version of F355 to work in full screen while also being somewhat integrated with Launchbox.
If, however you’re also doing a racing game arcade conversion or are similarly ‘insert coin’ inclined – read on.
If you intend to play F355 with a standard controller - stop reading The Dreamcast version is so accurate the difference isn’t worth the effort, it’s easier to setup and the sensitivity of the controls will work far better for you (ditto the PS2 version probably). I’ve recently acquired a broken F355 twin cab (well, half of one at least) so I set about with renewed vigor trying to finally get this game to work full screen using the Demul emulator.