I apologize! I had forgotten about this thread for a while now but I suppose I should report back!
Back in May, my wife and I successfully completed our rescue diver course with me wearing my bp&w! It was not that big a deal. We practised in a pool a few times until she could successfully pull me out of my BCD unassisted. Turns out it's not that hard:
1. Undo the waist strap (rescue breath.)
2. Take the crotchstrap off the belt - this is the tricky part that's worth practising! (rescue breath.)
3. Deflate the wing while sliding the BCD down my arms. (rescue breath.)
4. Done!!!
She killed it on the course and since then the staff at our local dive shop have been pressuring her to take the Divemaster course! lol!!!! For bonus points she also demonstrated to our instructor that she had a pair of EMT shears on her that she could use in a real emergency to cut me out of my harness very quickly!
Long story made short: Yes!! You absolutely can do your Rescue Diver course in a backplate and wing config!!!
Closing thoughts for folks who also want to do it with a technical long-hose configuration:
I also did the course using a long-hose configuration. Take this as a piece of advice if you plan on doing this yourself! Admittedly, this is not nearly as big of a challenge as having your buddy pull you out of your harness!

But I did run into some trouble with it because PADI requires you to wear a snorkel on courses. (I know, right?)
The rescue course did include an exercise that required me to donate a regulator to an out-of-air diver. On a long-hose setup this is obviously your primary. In donating it, the hose caught my snorkel and pulled the mask off my face!! FML... I found my self blind, with no regulator in my mouth, and with a bunch of water up my nose!
Luckily, I kept my cool and didn't panic. I caught my mask before it got lost, I found my backup regulator around my neck and resumed breathing, and I put my mask back on and cleared it before completing the exercise. Not a big deal, but a lot of excess stress for what should have been a routine out-of-air drill. Just remember to mind that snorkel when you take the course!!!!