This is not an issue with WS+ but has been since vanilla: In workshop mode, you can't open a door. You can select it and move it out of your way (then put it back when you go through), but without mods like Place Anywhere, some of the element doors added aren't pick-up-able by vanilla workshop mode. I know you said you didn't want to turn on true TCL and wanted to still have collision elements in place, but some of the city plans have lots of doors. I suppose I could just turn off auto-door close and open everything, but immersion man! I don't know if there is some way to make doors openable while in workshop mode, but just an idea.