My most recent flow is very similar, but I use AiderDesk[0] instead of Prompt Tower for easier creation/editing of plan files.
AiderDesk lets you save snapshots of a point in time, so I create "presets" to restore sets of context files and/or conversation history (you can restore one or both), which is a really nice bonus. You can also add/remove context as needed without the manual copy/pasting work when I forget to include something or accidentally included too much. Its VS Code extension makes adding/removing files from context seamless.
[0] https://github.com/hotovo/aider-desk