Yes, you can use
genuine Bit Char-G controllers for MicroSizers chassis and vice versa.
I do it all the time!
(At least the 27 frequency, the only one common between Bits & MicroSizers!)
You can even use clone controllers to drive your cars but...
The forward and reverse are sometimes switched. So to go forward you'd have to press the reverse button and the forward button to go backwards!
That's what happens when the ZZ controller is used to drive Bits/MicroSizers and when Bit/MicroSizers contollers are used to drive ZZ's.