I would, but you have to buy trials in order to do that. Just start a new flat world and see for yourself
In the last image, the world at the top is the world size of a nearly freshly created flat world.
Yes, my world has experienced this issue as well. When I try to move or do anything, my character will respond, but the inputs are super glitchy and delayed. Interacting is bugged, I cant crouch, run, or place blocks correctly, and buttons and stuff will not function.
Steps to repeat what Im experiencing.
Make brand new flat world in creative mode
Get command block and set it to Repeat, Always Active
set the command to /fill 55 -1 10 -6 -1 71 magma
Next to the command block, run the command /tickingarea add circle ~ ~ ~ 4
After a short while, the lag starts to appear, even after removing every block/entity in the world, including the command block and ticking area
I repeated these steps on Pocket Addition on my phone as well, and the issue is also occurring there as well.
UPDATE: It seems to primarily do it when magma blocks are filled