BONUS:SLOTS|SlottedIoun|x doesn't seen to do anything. It's coded for several wayfinders in Pathfinder Inner Sea World Guide and Seeker of Secrets.
Hmm, I suppose we could actually make this. I don't know why this is classified as a MAJOR issue though.
We'll see if this fixes your issue.
Sorry. Should have been minor.
But that still doesn't do anything. No slot appears in the UI for it. When equipping Ioun Stone, SlottedIoun does not show as a slot.