I'm really not sure about jumping from sbus to pwm I dont use sbub all my drone operate thru pwm... that's a question you either need to talk to a spectrum user or spectrum them-selves.. and there way more reliable brands then spectrum.I stopped using them many years ago as they dint stay with...
You can have 1 radio with a few receivers. we call each different 1 models.. so if you have a radio the will hold 20 model then you can have 20 different radio controlled rc on that1 radio.. you just switch between channels to use that Item..
the thing you want to know is how many channels you...