Yes, it turns out one can change session at login! Turns out Wayland doesn’t support my tablet, so I’ll stick with X11.

Thank you. This live USB defaulted to X11 for some reason, but I was able to change to Wayland after the session started.

It turns out Wayland doesn’t support my touch/pen-screen: "“Unsupported platform detected. Currently only X11 is supported”. So X11 it is.