It would be good to have a system ensuring that the player finds all the crops (maybe the crop system itself needs a rework).
I do plan on increasing the maximum sizes for all body parts, but for now, only to 9. 15 would be a lot of work, and I have other things I also want to add. I don't think I'll have the hitbox increase as size increases, because it would make the factory harder to navigate, and it could cause issues with the player or cowgirls getting stuck.
Milking yourself is not completely off the table, but I'll have to see if it works with the rest of the game.