Have you recently tried working without generating that plan? What I've been doing is first tell the model I want to plan the implementation, talk about it a few turns, then when I'm happy with the idea and method just tell the model to go ahead with the work.

Note that this is only really necessary for complex work that I don't know yet what the best way to do it is.

I've tried doing it your way as well, but there was just too much fiddling about with writing the plan somewhere, then having another session rebuild their context with whatever info is in the plan. It really didn't result in better output for me.

Currently 9 times out of 10 I just say to the model: xyz is the problem/bug/feature, fix it. Since about Fable and Opus 5, this is more than enough. Opus 5.5 (and previously Fable 5.1) got even better at this. However, this is in a codebase where there are already a few hundred thousand lines of code for the model to look at to see how we generally attack things in our codebase.

Claude Codes plan mode I never use anymore, it was useful a few months ago because the models had a tendency to just start doing work and forget I specifically told them not to. But the UX is just annoying and the models now do adhere when I tell them not to change anything.