If my goblin exemplar has the Burn It! feat and is using a Mortal Harvest ikon along with the Energized Spark feat to turn all of his persistent spirit damage into persistent fire damage, does Burn It! increase the persistent fire damage by 1? After all, it doesn't say "You also gain a +1 status bonus to any persistent fire damage you deal [with your fire-based spells and alchemical items]." It seems to be a much more permissive and standalone thought with no ties to the second sentence of the feat's text.
Yup, that's a legit interaction. +1 to any persistent does mean that a way to easily inflict just 1 base persistent is improved by Burn It!
IMO, way more feats should work like that, where they have genuine potential for "potency" in a niche that doesn't imbalance the game at all.
The feat author was very cleaver to flat boost persistent, as that's inherently capped to 1 per foe per turn thanks to the mechanic of persistent dmg being a foe-side dmg over time effect.
Even at level 1, it doesn't really cause any balance problems, despite likely doubling the persistent damage.