NC apparently uses the 2020 NEC. So insulation contact with SER cable is only an issue for sizes #10 AWG and smaller.
For outside of single family dwellings, #4/0 Al has a 75C ampacity of 180A, so it may be used for a load of up to 180A and protected at 200A. Likewise #2/0 Cu has a 75C ampacity of 175A, so it may be used for a load of up to 175A, and needs to be protected at 175A at most.
For a SFD supplied at 200A (via a service or feeder that carries the entire load), then those conductors, and any further downstream conductors, need only have an ampacity of 83% * 200A = 166A. In this context, both #4/0 Al and #2/0 Cu may be used for a load of up to 200A and protected at 200A.
However, if the SFD is supplied by more than 200A, then that 83% allowance would not apply to 200A and smaller feeders, and the usual non-dwelling unit limits would apply to #4/0 Al and #2/0 Cu.
Cheers, Wayne