You can just make a single shortcut-key to toggle between the two camera settings.
If it’s parallel it then becomes perspective: if it’s perspective then it becomes parallel…
I have Alt+P set up for myself…
I use scenes. My workflow for most architectural (not meaning that I am an architect - as I am not) work, is to create all plan views, elevations etc in parallel with corresponding perspective scenes at each subsequent view. ie: Scene 1/ Floor plan - parallel, scene 2/ Floor plan - perspective, scene 3/ Elevation A - parallel, etc, etc. I zoom to match each set and label the scenes, so it becomes easy to navigate and also port into LayOut.