The AV argument doesn't really hold up, because the planes they support have VERY long ranges. No offense, but just try running a seaplane base 6 hexes away from the Japanese perimeter and see how long it lasts!
As for the tactics required to refuel and re-arm PTs, players will have different needs depending on how they use them in game. So perhaps the better discussion is, are there any instances of AGPs serving as "refueling stations" for PTs? I tend to look at them as "torpedo providers" akin to the AS and AD, and to my knowledge those didn't refuel the subs and DDs they supported.
Fair enough on the AV question, I was thinking of operations from dot bases rather than proximity to the enemy.
As far as capability, NavSource lists the various AGP's with large gasoline bunkerage (62,000 gallons for USS Portunus, 105,000 for USS Acontius).
This does separate them from AS and AD, which as you say provided munitions and stores but not, to my knowledge, fuel.