I don't know what you are talking about. Do you want to tell me the direction of a switch is determined by the mainline that passes the switch?
I hope I misunderstood you. A left hand switch keeps a left hand switch. Done!
No matter if there is any mainline passing thru or not, no matter if it is just layed or still in the factory. What would you like to order from a rail factory? A left right hand switch because your mainline goes to the left? They would ask you going home till you know what you want.

But the problem keeps alive. And the F8-window understands the problem very well, a left hand switch is a left hand switch, because it is it's name and so it is displayed in the F8-window.

Look at the attachment to see how switches are called. Never ask for the mainline. Trust me, I know what I'm saying.