I love the writing of a Niri clone with this. Miri is a great way to express what Miracle WM can do!
What are your thoughts on going even further than Niri? Virtual outputs has some people asking for it. I'd be interested to hear how you think that might be modelled, how the plugin system might be able to express that. Stilch is the main Wayland example I know today with virtual outputs, https://github.com/wegel/stilch