Duke3D: Jump-crouch exploit still possible in certain areas

I mentioned this on Discord, and I'm aware that this is tough, maybe impossible to resolve -- but I wanted to document it anyways.

The original jump-crouch exploit from DOS involved holding both crouch and jump during landing, thus being able to pass through incredibly tight spaces. The severity of this has been reduced, however it is still possible to get into certain passages by jumping and holding crouch when landing. Unfortunately, these are usually shrinker passages.

Demonstration (E2L11): https://cdn.discordapp.com/attachments/461290354726010891/870759546459664424/2021-07-30_22-06-40.mp4

Another instance of this can be found in E5L4 (Mirage Barrage) of World Tour, which also involves a shrinker puzzle:

Note that by simply crouching, it is not possible to enter these passages.