Gardening - Harvesting

[Estellios]

Anyone know if you can feed feed two thavnairian onions back to back to get the chocobo to unlock up to lvl 12? Or do you have to get to level 11 before feeding the second onion?

I'm assuming you can feed the back to back because the onions "raise the upper level limit by one" which would imply that you can keep feeding them until you get to the cap of 20.