bcgreen- Hard to say if that'll work, but sure, give it a try. I'd use a milder pad/product combo with the PC and use the edge, myself.
3-4" is still a big space to me, I'd use the PC for that. I'd use a big pad (6.5 or even larger) so I had more overhanging edge to work with. I'd move the PC sideways as well as up/down in the area as best I could. The larger pad would make this easier.
But hey, that's just me and I've been doing this for a while.
It's worth experimenting to find a product that works well for you by hand *and* machine. You're always gonna have spots that you can't do by machine. I get good results with 3M's PI-III RC and MG (05933 and 05937) and the 1Z polishes.