I think from discussion with Gavin sometime during the montreal
scaling bitcoin workshop, XT maybe willing to make things easy and
adapt what it's doing.

If Core ships CLTV as is, then XT will have to adopt it - such is the nature of a consensus system.

This will not change the fact that the rollout strategy is bad and nobody has answered my extremely basic question: why is it being done in this way, given the numerous downsides?