I've recently been following turty wurtys tutorial on tree generation; however, I'm running into several different code bits in 1.16.1 (ex. implementing the abstract getTreeFeature() in your tree class) Have things drastically changed between 1.16.1 and 1.15.2 in terms of custom tree generation, and how so? I've been trying to debunk this for a while, but if I run into too many snags, I'll just use structure generation instead (which would help since my redwood tree's trunks are unique in comparison to any other tree in vanilla Minecraft.)

 

Also, my current mappings are 

version: '20200723-1.16.1'

which I've heard is currently the most stable mapping, but this is just for reference

3 hours ago, Kyberkreeper said:

Have things drastically changed between 1.16.1 and 1.15.2 in terms of custom tree generation, and how so?

Nothing has changed between those two versions. However, you should update to the latest minor.

3 hours ago, Kyberkreeper said:

which I've heard is currently the most stable mapping, but this is just for reference

It's a snapshot mapping, not stable. Nor is it the latest. That can be found by dming forge-bot '!mcpv' which is present on the Forge discord.