The funny thing is that in some cases using a different harness with the subscription plan could actually be very good for Anthropic: e.g. if I were to use smol

The funny thing is that in some cases using a different harness with the subscription plan could actually be very good for Anthropic: e.g. if I were to use smol with Opus, it could use fewer tokens than CC for the same task. People on subscription plans burning fewer tokens is a good thing for Anthropic. The only downside for Anthropic that I can see is that hitting your limits more often (while using CC) could make you want to upgrade plans, and a more efficient harness could keep you from doing that. But I can't imagine the cost (to Anthropic) of those inefficient tokens is worth it to them.