My usage is nearly the same as OP. Plan plan plan save as a file and then new context and let it rip.
That's the one thing I'd love, a good cli (currently using charm and cc) which allows me to have an implementation model, a plan model and (possibly) a model per sub agent. Mainly so I can save money by using local models for implementation and online for plans or generation or even swapping back. Charm has been the closest I've used so far allowing me to swap back and forth and not lose context. But the parallel sub-agent feature is probably one of the best things claudecode has.
(Yes I'm aware of CCR, but could never get it to use more than the default model so :shrug:)