Personally, I think access to any of the line of ancestry feats introduced in LO: Impossible Lands with Fey Influence as a prerequisite would make for a fantastic boon. This could either include Fey Influence itself, or be a purchasable add-on for those who earned the chronicle boon awarding it. Either way, I really love how flavorful they are as a sort of sub-heritage, as body-altering powers that largely developed out of the user's control.
