When you use Grand Tree Pod seeds while in the Grand Tree, it says you cannot use them. You need to teleport out of the Grand Tree in order to level up farming. Also, if someone who is crazy about fail statistics of xp training methods (Zodz), he would probably calculate this is faster than the normal methods, which is entirely untrue.
Imagine, you get 100xp per launch which takes ehhhhh ~10-15 seconds.
At level 72+ Farming, you can do tree runs that get you over 150K/day.
You just got logic trolled.