didnt really have time to read through, but i thought it was worth noting that you can be killed by tank shells just as easily as normal [like if you were just standing behind the directly behind the tree). So you should probably make sure not to let tanks see you if you're doing this glitch while tanks are around.
me and a friend were just messing around with the other elevator on outskirts and we ended up coming back to the tree and he wanted to see if a tank could kill me while i was in there, and it could xD