Well, I got it working by attaching container and running "startx -- /opt/bin/Xwayland"...
Run "su user" first to start non-root...

update - not consistent ... Worked one time, then, after reboot, wouldn't work, (server error - couldn't add screen...). Also got it to work one time simply by typing "/opt/bin/Xwayland" ... Not sure what makes the difference .

update - found a method that works, using Containers app, and tips from here - https://talk.maemo.org/showthread.php?t=98882

- open Containers app, and select container, and tap "start Xsession", (nothing happens visibly, but won't work if I don't do it), then tap "attach ". Terminal will open asking for root password, then show Linux root prompt.
- enter "mkdir /run/user/0" then "export $(dbus-launch)" then "export XDG_RUNTIME_DIR=/run/user/0" then "startx"

Desktop opens...