Whenever a player crouches on a Trampoline to charge it up, then jumps off of it while still crouching, the block will retain its current blockstate until jumped on again.

Here's a small video showing it:
https://github.com/dayofpi/super-block-world/assets/160932138/fa48af73-3137-436b-9799-4719c9f4e950

Here's a screenshot of it (If the video won't load):

MC Version: 1.20.1
Forge: 47.2.0
Super Block World Mod Version: 0.0.8-1.20