Something I wrote about last year, was that NVIDIA were working towards better supporting NVIDIA Optimus on Linux. Seems like another step is being made towards that end!
In the proposal sent to the xorg development mailing list from NVIDIA's Kyle Brenneman, it goes over how they would expect it to work:
For GPU offloading in libglvnd, where individual clients can run with an alternate GPU and client-side vendor library, we'd need some way for that alternate vendor library to communicate with its server-side counterpart. Normally, the server's GLXVND layer would dispatch any GLX requests to whichever driver is running an X screen. This is a GLX extension that allows a client to tell the server to send GLX requests to a different driver instead.
In the proposal you can find a draft of the extension spec too. You can also find the WIP (work in progress) merge request here on the xserver GitLab too where Brenneman is hoping for some more feedback as they currently have none sent in reply to their proposal.
This is something that has been a pain point for Linux laptop users for far too long, perhaps there's now finally a light at the end of the tunnel. It certainly would make choosing a laptop a whole lot easier in future if this all works out.