(Disclaimer: This issue has similar (issue). I wrote this for more clear and understandable issue: MCPE-163424)

"Crash kept on happening in world when enabling 1.20 features"

That sentence has a similar issue for my device, Huawei Tablet T10: Android 10. The tablet had 2 variation, One has 2GB RAM and the other has 4GB RAM, Unfortunately I use 2GB.
Before this beta is released, mcpe dont that usually crash I even download mods with no issue.

Steps to Reproduce

1. Create a new world in latest beta with 1.20 experimental features enabled
2. Wait for a few minutes

Suppose to be : Crash will not be happening in world when enabling 1.20 features

FAQ: 
what device model are you using (brand and name)? Answer: Huawei T10
Are you enabling the Experimental features before you create the world or after? Answer: before and after (depending on the situation)