The section about handoffs being frustrating is the same thing ive experienced and why i built https://github.com/TStansel/handoff.

Goal is to be able to transfer context from one agent to another when switching which provider is being used. So when i hit usage limits on claude i can can run handoff claude codex and codex is given a md file to start from and continuing working.

Still early but ive found it useful in my daily flows already!