Yeah so Magical/transmutation should work based on how I’m reading it as a standard staff. Since magical is listed as a trait, that’s where you could swap it out.

I'm going to wrap back to this in the morning and write up a bug card myself, it'll be easiest to be sure we get the specific info we need to adjust this. So to confirm:
1. The theme trait (Plant) isn't being assigned to the list of item traits on the staff, but is correctly limiting spells selected.
2. The school trait (Transmutation) is being assigned, and does not need to restrict spells since it is merely assigned to the item, since all items have an associated school.
3. There is no option to select a spell tradition, which also needs to restrict the spell options, but is not required. It replaces Magical if selected (because everything with a tradition trait is understood to also be Magical).

Yes, that's my reading as well, Daniel.