RCP needs to mirror the ceiling like you're laying on the floor AND it needs to be in alignment with the floor plan - so you likely do need to flip it to match the top down (plan) view in the viewport.
then add the LO scrapbook electrical bits as needed.
i made custom components for use in SU to lay it out and then set a scene to use "show_symbol" vs object (so it's 2D). then unless it's some very specific wiring that needs to be shown in SU, i'll add any electrical lines between them using the layout lines to color them, size them etc.
this way i can flip from 3D to 2D quickly once i've positioned everything. do a "bottom" view (might require a section cut if i have flooring etc) from the standard perspectives, then flip in LO to mirror the floor plan.