Yeah I noticed the preview pic was pre-Sigil II but I've seen other posts about the episode menu made after Sigil II, and it all still fit.
It actually just barely still fit after adding in the episodes from the Master Levels, so I ended up doing a little futzing with the menudef after all. I changed the spacing to 16, which I just think looks nicer, and ended up changing the menu position so it looks more centered. Only thing it bumped into the "Which Episode?" patch so I moved that up into the negatives, which turns out as soon as it's negative anything it just shoots up to the top of screen. A little weird, but whatever I guess.
This is the menu after setting the title patch to 50, -1 and the position of the menu itself to 30, 0:
I'm not... super happy that I can't seem to make the title patch go a little lower? But when you're dealing with such a huge list of episodes you do kinda need to make sure you have plenty of room for them all. I could just get rid of the "Which Episode?" heading altogether, it's not like what this menu is for is going to confuse anyone who plays it (just me), and technically most of them aren't really "episodes" under the Doom 1 definition anwyas.
Quake 1 technically has more episodes but you select them from those in-world introduction maps, so even the remastered version doesn't need to cram as much crap onto the screen as I'm trying to do. Considering the all of that I don't think it looks too bad.
I'm on the fence about keeping that custom, not all caps version of the Sigil 2 patch. I made the author-defined ML episodes white to match the box art because I thought it would look cool and since Sigil is already doing the Nightmare font thing I might as well add in a little personality for other stuff too. I mean to this day retail releases only ever treat Master Levels out of the box as 20 individual wads or an single episode, and neither of those approaches actually reflects what the handful of maps with an actual plot are about, so they've always sort of stood apart from the other episodes in that way.
But at this point it's all just fiddling around, the actual problem I was having is solved. So WadSmoosh rules. Now if I can just figure out how to swap between the Sigil soundtracks without having to close and reopen GZDoom I'll have the perfect iwad...