Hi!
I am the creator of Boom-puffs, your mod is fantastic! I had been meaning to make this functionality for the longest and didn't think it was possible, so I had to quickly download and read your scripts. I had been doing a similar thing with another unpublished mod regarding tamed pentapods to do the "planting" through scripting, fake temporary tree spawners etc but it was always a huge pain, and I didn't want to make all these copies of plants for each quality etc.
Anyway, I just made my own version (after asking for Agricultural on_events - which trivialise much of the process!) I thought I'd ping you to let you know the new API for the AgTowers Which may or may not help streamline some of your control lua. Also check out my mod, which hashes the trees and fakes the sprite if your interested =)
Cheers, and epic mod!