There are plenty of OWEs that spend US$100k on CX annually over many years, sit quietly in F and don't even consume alcohol, and there are OWEs that "game the system" and only fly CX on short haul on Y and arrive at the airport 8 hours early to lounge hop and only fly in premium cabins on partner redemptions which they then "maximize" for insta.

Incidentally, I think the former is far more common than the latter. CX also does a very good job of tracking passenger's spend (even non members) so I am certain they can distinguish between the two. As for upgrade priority, I just got upgraded to F on a long haul with my OWE on the booking, completely full flight, and it's not the first time, so I don't think the upgrade priority is quite that straightforward.