My understanding is that the 22K main to 10K branch would be the same as a 22K main to 10K feeder to 10K branch.
OR- 22K main to 22K feeder to 10K branch.
Most of the lists, in panels or other documentaion I have seen, seem to reflect that.
And would accomplish the same thing. Really depends on the list of allowable breakers.... (Which seem to be, any that THEY make.
What I have always wanted to know is. If Company A claims thier 22k breaker will accomadate 22k for the 10k breaker of Company A. Why would it not withstand 22K for Company B's 10K breaker?