Hi Oliver,
That is a fantastic and kind idea of yours to gift a tree for that reason. What do you mean by someone having engaged with my habit? If that person already engaged (used) your habit then it is already an adopter. If you thereafter gift a tree with the same planting habit and that person collects the tree, it doesn´t add another adopter because this person is already an adopter.
Please clarify what ´had engaged with my habit´ means. In the meantime, I will confirm the adopter count with a tree gift. Great questions :)
It is fantastic to see you build the CalledTheVetAnyway planting habit - https://tree-nation.com/habit/CalledTheVetAnyway