Suzuki started the silly trend of running the connected hose over the front guard. AMA race rules for instance insist on two separate lines. They are easier to bleed and less prone to issues.

But I've never experienced what I assume you are saying.

Actually what are you saying?

Take it for a test ride down the street. Don't touch the lever.
Does either disc get hot?
If they are dragging they will. There will always be a negligible amount of drag, but not enough to get hot.

But I read as saying that after a ride using the brakes as normal, one side stays cool. I'd kinda expect the system to be unable to operate much at all if there were that much air. How much lever travel are we talking?

Can you feel/see either disc flexing when brake lever??? Nah there'd be hell noise.