I think some of the other answers here have encapsulated my concerns pretty well.
I am talking about one lap, often with one protracted climb that dominates the map, but the overall duration is much more XCO than XCM.
I’m rolling with the notion that overall duration is probably the stronger marker when choosing between XCO and XCM, but given that we have seven different disciplines just within off-road training plans, it feels a bit like XC is adrift with more emphasis on a longer steady effort than XCO, but much less emphasis on an all-day effort than XCM. I suspect that XCO will suit me well enough, and mercifully I am built largely of low-hanging fruit, probably making it a less crucial decision.
And not important to TR in general, I’m just personally startled that XC MTB as I know it regionally and as I imprinted on it years ago isn’t even recognized either in TR’s or Wikipedia’s disciplines lists.
I’m happy to roll with XCO without further response if that makes sense.