I will keep searching -- if I find a solution I'll post it here. Your time and efforts to help are much appreciated....
Did you get package-related errors? I also tried to install LXQT Full from Architect earlier today, and all 3 times it failed with package-related errors. Minimal install worked OK.
I could not install the full version from Architect, either. Had to go with minimal. I still haven't been able to fix the issue that I originally brought to this thread.
Sounds like a major bug, devs should take a look at this.
In case anyone else is confronted by this issue, I finally found a way to autostart an app that requires authorization in LXQt.
I did a clean-install using Dalto's beta community LXQt spin, thinking that the issue would be fixed in this newer rendition. Unfortunately, no.
After further extensive searching around policykit and its various gui implementations, I decided to try adding "lxqt-sudo" to the exec line in /.config/autostart/eddie-ui:
[Desktop Entry] Exec=lxqt-sudo /usr/bin/eddie-ui Name=Eddie-UI Type=Application Version=1.0
Now I get an authentication gui after booting -- in fact, I get TWO of them and haven't figured out how to get rid of the second one, but that's another story. After inputting my password, the app starts up. For now, I'll mark this topic [SOLVED].