Understood, but that doesn't help it if it has no role in scenarios (it doesn't and nobody has suggested a viable one) and is too weak and slow to get MA use.
FSO often had "recon" missions in the past, which would be exactly the sort of thing for the PBY. I once proposed a spin on the Midway FSO where one side didn't get to attack the enemy's fleets unless a recon mission successfully spotted them. It was something like:
Frame 1 - No CVs are targets. IJN attacks Midway, US defends. IJN and US send patrols to locate enemy fleets (PBYs and solo B-17s for the US, B6Ns in lieu of cruiser/battleship-launched float planes for the IJN).
Frame 2 - Any TGs spotted in Frame 1 are added to list of targets. Otherwise frame proceeds as Frame 1.
Frame 3 - As in Frame 2, only no more patrol flights.
Oh, and even if they're comparatively weak, Black Cat PBYs would still be a hoot in the Mains. I've also suggested that the PBY could also make enemy TGs appear on the map in the mains for X amount of time after contact is made. The longer the PBY is able to shadow the boat, the longer the map icon is visible.