MCCs are UL listed under UL845.
UL845 requires very specific testing of each and every possible combination of devices. Technically you cannot even use a different Siemens breaker in a Siemens MCC bucket if it is not the exact same Siemens breaker that came out of it. The UL label on that bucket is for the exact components that were in it at the time it was tested and listed under the manufacturer's UL845 program. There is some leeway allowed for when a specific part is discontinued and there is an official replacement, because usually the mfr. will submit documents to UL stating they have evaluated the conditions for its use and it will perform at or better than the level of the original. But UL charges them for making that determination.
Can some breakers be used in other brands of MCC? Maybe. Going back 20 years or so, there were more MCC manufacturers than there were circuit breaker manufacturers. So people who did not make circuit breakers, such as Allen Bradley, Cutler Hammer and Furnas, were forced to buy breakers from competitors, usually ITE and Westinghouse (nobody else ever used Square D breakers). But over time that changed: Cutler Hammer bought Westinghouse, Siemens bought ITE, then they bought Furnas. Ironically when I worked for Furnas years ago, they changed from using Siemens to using Westinghouse, and made Westinghouse pay mega bucks to re-do all of the UL listings on the Furnas MCCs, at the time about $8K per line item. Then 2 years later Siemens bought Furnas and switched everything back, hardly cost them anything because basically nothing had changed from the original designs. Allen Bradley flip flopped between ITE and Westinghouse, especially after Siemens bought ITE. Although A-B now sells circuit breakers they do not make them, they are the Cutler Hammer G line breakers brand-labeled. But does that mean you can swap out an A-B breaker for a C-H version of the exact same thing? Maybe, maybe not; it all depends on whether or not A-B paid the extra money to UL so that the "also listed" label could be applied. And what do you think are the chances that A-B would have paid that extra money? About zero...
So bottom line, you cannot put ANY power device into an MCC bucket (or switchboard or panel board) that was not originally listed to be in there unless the manufacturer tells you that it is permissible under their UL file, and none of them are going to do that in a way that gives their competitors a chance at taking the replacement parts business away from them. MCCs and most other assembled gear is a loss-leader for mfrs, they do it specifically so that they CAN get the replacement parts business later. They are not going to make it easy for a competitor to grab the frosting off of the cupcake.
