If you talk about the random generator acting up, I very much expect them to switch to their own PRNG at some point. Until then, I’ve posted a fix for that. You’re free to re-distribute that smod anywhere or simply include that line in your code.
I would personally recommend to not hold too much for the tree variants. For your project, I wouldn’t touch the trees at all.
The issue is like I have mentioned somewhere else, even if you override everything, the entity is still called stonehearth:small_oak_tree. Let’s say I’ve written a very badly scripted mod (rp_chainsaw) which allows cutting down every tree ten times as fast and yields a thousand logs per tree. For that, it simply mixintos all stonehearth:*_*_trees.
Now your candy tree can be cut down by my chain saw and produces lots and lots and lots of wood - something which is not necessarily intended.
Overwriting and mixintos are powerful tools, but you have to keep in mind that other mods will, in the end, expect at least the original entity. They can’t (and shouldn’t have to) know what you have done to its definition.
My offer still stands regarding the json_to_lua error, send me an smod where the error happens and I’ll take a look.