I think it would be very helpful if you were able to create a "Tree" mod element, in which you specify a sapling texture, which blocks it can be placed on, whether or not it can be bonemealed, and more like that, as well as defining up to 5 or 15 variations of the fully grown tree.
To go along with this, Biome mod elements should have a third option for trees in the biome; selecting one you've made. Both of these together fix some issues with trees neeing to be structures, and sometimes they generate weird (floating, underwater, deleting terrain).
MCreator issue tracker has been migrated to GitHub.
Existing tickets have been migrated to GitHub. Please open new tickets on the GitHub tracker instead. If you do not have a GitHub account, all feature requests and bug reports from forums are still considered and checked by the maintainers.
Custom trees and generating them in biomes
Status
Resolved
Issue description
We do plan to add better tree support down the road :)