AFAIK PostMarketOS seems to be working on something similar - my PostMarketOS edition PinePhone even shipped with a convergence hub:

https://www.omgubuntu.co.uk/2020/07/buy-pinephone-postmarket...

BTW, I think the convergence concept is totally valid and actually available now (although in a proprietary form) as Dex on Samsung Galaxy series devices.

Just plug the thing into a USB-C HDMI dongle and it shows a desktop interface on the display & has decent mouse and keyboard support.

Really nice for simple stuff like looking at photos you just took outside but on a big screen. And also a killer combo with the Wacom One pen display as you have your Clip Studio or Krita files all available on the big Wacom One screen yet can work on them on the regular device screen while on the go. :)

So now we just need that, but open source. :)

It could be a separate wayland session outputting to the external display with app GUI getting data from a backend via DBus. That way you could run the same up on both device and external screen at the same time while keeping the data model consistent. :)

> So now we just need that, but open source. :)

That's the whole idea behind Librem 5 and PureOS and it already works well. All the phone apps there are just regular desktop apps made convergent to fit and work well on the phone.

See https://www.youtube.com/watch?v=onxBw5Pd45w and https://www.youtube.com/watch?v=9qB_5g2ZJYk

From my limited perspective as a former user who still keeps up with some of it: they seem to be continuing down that path, just slower as they don't have Canonical's paid dev team to work on it.