I'm guessing wildly here because I have no knowledge of what's going on under the hood, but testing has revealed the following:
- Loading just Hideous Destructor works most of the time.
- Loading HD with mods like AutoAutoSave, Tilt++, or DarkDoomZ causes crashes with an access error (pastebin'd example: https://pastebin.com/C44kJjtB)
- Loading HD with a level seems to work about as often as HD on its own does.
From this, I suspect that either there's memory allocation shenanigans, or loading multiple mods that add similar resources causes the crash (HD, DarkDoomZ, AutoAutoSave and Tilt++ all use ZScript extensively, but the levels I tested with are pre-ZS).
EDIT: HD was always loaded first in my tests. May have to check load order later.