And I'd love to make it for iPads too, just struggling to find the optimal UX for enabling and disabling the overlay.
On macOS you can just use the global hotkey or the app menu, on iPad I'd have to wire it up somehow else - supper happy to get ideas on what would feel seamless and unobtrusive for you. I'll definitely implement it then!
What about a control center toggle? Works alright for toggling the windowing system. In general having shortcuts to set it on/off/toggle would be great.
This might work! I'll implement this and see how it feels, thanks.