at what PAL address is this value located?

[Seeky]

The 0x808B5FC4 vtable means that the vtable field of this class contains a pointer to that address, not that the class is stored there. There's no fixed address for this value, each player has their own unique instance of this class that spawns in a 'random' location in RAM each race. You'll need to load the pointer stored in PlayerHolder:: sInstance (which is at a fixed address), then work through the chain of sInstance->players[idOfPlayerYouCareAbout].pointers.playerSub10->floorCollisionCount