@mkoff About SIGIL:
It is a Core Limitation, I recommend that you rename WADs in a more "coherent" way:
Where to write to add ports? There is no normal life without Heretic, Hixen and Duke Nukem 3D!
There is Libretro cores for this games?
Recalbox developers only add open source cores, which already exist, if they focused on inventing a core for each game there will be no further improvement in Recalbox...
I recommend you use DOS for these games: