I feel that you are arguing against yourself. In this thread you want things to work without having to use any key combinations so that a new user doesn’t have to read the manual or take a class. In the Use of “Set XYZ Coordinates thread you are advocating that more key combinations are added - that probably nobody will find out of.
Yes, I am sure that many new users get frustrated but in the end it’s like learning how to ride a bike; it takes perhaps a week of training and learning how it’s done. That doesn’t make it rocket science.
A lot of the assumptions that you are imposing in that example are just plain and simple pilot error.
That said, have you tried the AutoCPlane script that Pascal wrote and that will be part of Rhino 6 in some form? It makes it possible to work in the maximized perspective view at all time (so that you get visual feedback about where your snaps are going) but still make use of the other CPlanes. In perspective view with the top CPlane active, I can start that line at 0 and then rotate the view until the Front CPlane just becomes active (I would rather rotate to the Right CPlane but the instructions say Front). At this point I can still distinguish between all the lines (they are not hidden by each other) and I can snap to the correct place to end the line. No extra keys were pressed.
AutoCPlane.py (9.0 KB)