I have a JRxs3 with two RS300 receivers.
You'll just have to test it. Borrow a Novak XXL from someone and run it. The frequency bands will have to be the same though......obviously you know this....75MHZ and 75MHZ.....or whatever you're running
My RS300 receiver is also mounted on top of my JR servo, no problems whatsoever. In fact, 7 of use a JR radios within the same class, so, no glitching even though we race at the same time....
My NTC3 uses two Futaba 3004 Servos, no problems there either.
The only time I ever had glitching problems was when I used an AM 27mhz Associated crystal in my Futaba receiver, I guess I was looking for trouble.
Hope it helps