> It's explicitly partially monotonic.

From the RFC:

    Monotonicity (each subsequent value being greater than the last) is 
    the backbone of time-based sortable UUIDs. Normally, time-based UUIDs 
    from this document will be monotonic due to an embedded timestamp

"time-based UUIDs from this document will be monotonic". "will be monotonic".

I'm not sure how much more explicit this can be made.

The intent of UUIDv7 is monotonicity. If an implementation is not monotonic then it's a bug in the implementation.