My workflow involves occasionally turning my screen 90 degrees (e.g. to read a document or edit a portrait picture), but only temporarily. I use KScreen to switch the orientation of the display. Plasma helpfully moves the plasmoids I have on the desktop so that they fit (horizontally) in the new dimensions. When I'm done, I turn my screen back and change the display orientation back to the original in KScreen. The plasmoids do not move back to where they were originally - instead they stay where they were moved to (relative to the left side of the screen).

I put my plasmoids near the right side of the screen, so they end up shifting to about the middle, and I have to manually drag them back every time. This is a pain.

Reproducible: Always

Steps to Reproduce:
(0. Assumption: Your display is not square.)
1. Place some plasmoids in various locations (at least one near the right or bottom edge of the screen).
2. Use KScreen (presumably any xrandr client would also work) to rotate the display 90 degrees.
3. See on the desktop the positions have changed to fit in the new screen dimensions.
4. Rotate the display 90 degrees back to the original orientation.
5. See on the desktop Plasma has forgotten the original positions as they have not changed back.
6. Move all of your plasmoids back to where you put them to begin with...

Actual Results:  
Plasmoids are shifted, user is annoyed.

Expected Results:  
I think it would be useful for plasmoids positions to be stored independently for different screen orientations. Then if positions are present for an orientation Plasma can just use them, and if they're missing, Plasma can generate them automatically. It also gives the user the ability to tweak things for each orientation - because how likely is it that automatic repositioning is going to get things "just right"?

I checked the 5.7 changelog to see if anything seemed to address this, but spotted nothing.