I'll put up my experience with the PD droop. I used one on my boat prior to setback, shoe, and rideplate. It helped on my boat, but there are no guarantees that it'll work on you friend's hull. It'll have to be a try and see thing. If he's really a pal, let him try it first to see what it'll do for him. He's going to wanna try some wedging both up and down. Mine liked 4 degrees up, but his may be different. If you can scrape up a good selection of wedges 1, 2, 4, degrees he could try different combinations. If you can find the plastic ones he can stack em without having to use gaskets in between. I set mine up with some allthread so I didn't have to buy a bunch of different length bolts.
Obviously he'd get better results and tunability with the shoe and plate, but it's possible that it'll work to some degree without the rest of the hardware.
Dan