It can't account for things that only come up during implementation. But you can explore much more of the design space in planning to reduce the opportunities for Claude to wander down the wrong path during implementation
The plans usually end up very long and verbose, and in my most vibe-y test project I stopped even reading them myself and instead just ask questions interactively. e.g. "what are the remaining unanswered design decisions", "which part is jankiest". It does work quite well although I don't know how I feel about it.
P.S. to any anthropic staff: The "chat about this" option in Plan mode is useful but also annoying. When I select it I want to take the next turn of the conversation myself, I don't want it to waste time "thinking" just for it to verbosely ask me what I want to chat about.
Your summary approval idea is interesting and feels maybe like a mini plan mode. My biggest frustration with the existing manual approval system is when Claude is exploring it gets tedious to approve each command. Being able to approve a block of commands or a mini plan AND have auto mode audit them for safety would probably be something I would consider for the expiration phase of my Claude use.