Sway-wm used to be spawnable as a child window, not sure if that is still possible.
I think you should also be able to get multiple ctrl-alt-fX graphical sessions.
I’ll come back and update this comment when I get to my PC and give this a try.
Edit: seem Max-P’s comment.
The malware argument is a bit weak, if your router is vulnerable to something it’ll likely be found and pwnd in a matter of minutes, so turning it off a night won’t really save you. And once a patch is released, it’ll be reverse engineered in a few hours/days, so ideally you want patches as soon as they are released.
Using your own device is usually a good idea anyway, telco stuff is usually pretty mediocre. And as soon as your device is slightly custom, it becomes a less valuable target.