Thanks again. You'll probably see a lot of short textures on tall structures from me, I like how some of them repeat, but never really considered how it might affect true Vanilla doom. I suppose it might disqualify me from being able to say that they're strictly Vanilla format or at least from saying they're fully functional, although I'm not sure that it would "break" vanilla doom assuming you mean crash it. I'm only basing this on the fact that I probably had similar things happening in my first map which I tested in vanilla doom, and although I did get some rainbowy errors on the vertical tiling here and there, it didn't crash or anything. Again it's something I don't really encounter. Plus as you've no doubt noticed I like large areas so I can't see myself changing those habits, and I've used those various 'steps' textures for all kinds of effects, such as simulating a chest of drawers or mail slots in a mail room.
I guess if it's working with ZDoom and similar ports that's good enough for me, newer computers are necessitating them anyway. Perhaps I should find some kind of term to describe my specific style of map making if it's not completely vanilla-compatible. Sort of like those vegetarians who eat fish have their own word. And after all, I do have some maps that rely on actors not being infinitely tall, which of course is a vanilla feature.
There were a few times when I intended to sound-block but I can't remember if I ever got around to adding those in or at least making certain monsters deaf (some are but I recall the final hoard wasn't for the longest time). That level's also open ended enough to where it plays very differently depending on which way you go. Some people find the rec room immediately, and others don't see it until the very end, the latter scenario definitely leading to door blocking.