TBH, the only 2.5 amp chargers I have are Samsung fast chargers that came with my cell phones. At one time they worked with no lightning bolt, but one update that changed. So maybe there's something in the pi or charger circuitry that prevents it from kicking up to the "fast charging" 2.5A

One less cable going to the pi is always a good thing, I hope the PoE hat works out well for you or your friend. Not sure if that one was for home use or a retro pie