@reliquia
I have included 2 screenshots 1 in realtime and the other prebaked (lightmapped- function key 2) I took a walk thru both and no trees fell down.
I need to empathize that I'm working in the public preview version of GG and all of my tree and tree related models require the fpe file to contain the apbr.tree.fx shader. I believe this shader includes the same fix for the original leaf ghost problem as does the tree_basic.fx shader included in the pre public preview gg version. I need to note that trying to use my trees in any pre-pp beta version will cause gg to fail. This is explaind in the store versions of the models.
The big difference between the two screenshots is the lightmapped one does not show cast shadows on the ground whereas the realtime does a much better job with shadows overall. (It took 2 minutes to prebake) I understand that lightmapping is not really working fully yet in the pp version.
I'm no expert when it comes to the falling tree problem you were having, but I think it has something to do with the static, isimmobile and collision settings in the your tree fpe files. Perhaps when the pubic preview version is release as current beta you might make another attempt with the cartoon trees.
I like your decaying stump suggestion and will see what I can do.
Windows 10 creator,64 bit| Intel i7-7700 @3.60GHZ Quad|CPU PASSMARK 10,794|Memory 16GB |NVIDIA GEFORCE GTX 1070|GPU PASSMARK 11,071