Hi again, guys. So, I used a nifty tool called WadSmoosh to consolidate all four doom IWADs that I owned into one .pk3 that is usable as an IWAD in G/ZDoom. One particularly big advantage of this is that you can play Ultimate Doom with Doom 2 resources available, from textures to things. Some mods don't play well without Doom 2 resources available. The reverse is also true, for the few textures Ultimate Doom has that Doom 2 doesn't.
So if I wanted to make a module that releases the restrictions on which games can use which resources, allowing Doom 2 monsters to appear in Ultimate Doom and allowing prefabs from either game to be used any time, where would I start?
I'm not especially interested in having the ability to generate a wad for the literal entire Doom saga, because if you generate one for doomu and one for doom2, then load them up together, they work fine without stepping on each other's toes. You can choose what to play at the episode selection screen.