I think this role needs to made limited to 1 per a game. After much thinking, I noticed that the tree makes game not winnable to often. By putting a 1 tree limit on the game, it reduces this to only 3 that I can see.
A survivor can hide at 3 way lylo, with no chance of being killed, and maf can not kill the tree instead. At 3 way lylo Non-killing maf roles can not trick a town to lynch wrong nor kill after the forced nl. At 3 way lylo, a Tree and a Granny will make maf just ns because they can not win. Either way I think the tree role doesn't really work on EM, even if it does in forum games.
Honestly, I expected whoever visits the treestump to do an acrobatic pirouette off it and die. At least make the tree's role visible when it becomes one.