I should have updates shortly, but the main thing is you need to use PVC cement to prevent bending, sag, etc.
Although the panels were screwed to the joints, there was enough slop for them to sag bynhaving the pipes rotate.
Using PVC cement locked thempanels flat and stiff. Also fixed the base.
Still experimenting with the upright (and the screwdriver body fits loosely into a 1-1/4 coupler).