Correct.
Maybe, but that shouldn’t be necessary in this case because, as per the link in the previous post, as of almost 4 years ago the necessary APIs have been made available with Gnome using Wayland to allow remote desktop protocols generically (whether RDP or VNC) and the VNC server updated to use it.
The problem that I came up against is that the settings for the VNC server did not come up in Settings on the Librem 5, so it isn’t obvious how to enable it or how to configure it. Needs more investigation.