Problem wads for floors, crushers, lifts

Yea, this is an attempt to pick all your brains, as I expect some of
you know about this already. I can make fixes, but need to know which wads will break when I do.

I tried to fix DoomLegacy for Doom2 Map05, where the secret rooms with tag 9 would close off.

Then there is Doom2 Map06, where the spider demon would gum-up the crusher. It must crush twice to finish the job.

I know about monsters getting being in a crusher can cause it to fail,
gum-it-up, preventing the return stroke (up on a crusher ceiling).

Any more problem maps that I ought to know about ???

Any wads that use the instant-move side-effect (when dest is to wrong side of movement direction) to crush someone,
or could crushing be disabled for such moves ???

Extremal Doom E2M7 has some stairs that can crush and behave differently and somewhat unpredictably in differing exes. Some discussion here (and subsequent posts). Judging from that post, Icarus map29 also has a similar issue. Entryway knows more about this than just about anyone, I suspect.

Grazza said:

Extremal Doom E2M7 has some stairs that can crush and behave differently and somewhat unpredictably in differing exes.

Do those "stairs that can crush" behave similarly to those mentioned here, by any chance?

My theory is that all instances of "crushing stairs" are actually either freak sector types (randomly generated and matching strobe damaging floors) or a weird engine glitching which triggers the normally unreachable floor/stair crushing damage code.

AFAIK the vanilla mapping format has no concept of "crushing floors" (you can't simply put one on the map as if it was a crushing ceiling) yet the code for rising stairs does include crushing damage modes, which is unclear when and how it can be activated.

Still, the damage inflicted in the demo linked is instantaneous (-20%) which makes me think more of damaging floors/strobe damage, rather than a crusher (also, it doesn't hinder or trap the player).

After reading all that, it is a bit confusing, and expands the question a bit.

What I get so far is:
UDS: fast stairs crush, slow stairs do not,
see Revelation TVR1.WAD
( but "Cyberdreams" relies on slow stairs crushing ??? )

I was more wondering about stranger uses of crushing, such as any crusher ceiling starting below its neighbor ceiling and insta-moving to the dest height and invoking crushing damage. I hope there are no wads relying upon such behavior.

I have noticed that Edge1.35 has its correction for overtravel without crush damage.
Other ports keep passing the crush variable, even when there should not be any crushing, such as the up stroke of a crushing ceiling, or when detecting dest to the wrong side of travel and insta-moving to the dest.
I am considering passing crunch=0 in such cases, but am developing a flinch from discovering so many weird wads using every obscure bug.