Not sure if this is intended or not so i would like to bring it up.
you can place fully loaded Shulker boxes in the inventorys of the different aircrafts.
this could potentially cause tps issues and chunkbans by overloading them (potentially of course)

was wondering if this is something the dev is being aware of. maybe it makes sense to disable shulkers from being put into the inventory of the plains.

thanks.

Are shulker boxes blocked in boats as well?

I tested it; since you can place boxes into chest boats this is a more general problem which should be fixed by a separate mod for all portable inventories.