If this was really an issue all of the regulations regarding trailer brakes would have addressed and solved the problem.
I had stainless steel disc brakes installed on my old 86 Triad by Triad Trailers. I received a folder full of printed material. It had warranties and all sorts of Cover Their Backside info,
Nothing mentioned about the quick release allowing air into the brake line. Just my thoughts and 2 cents.
It mentioned checking your fluid level. After a few years of disconnects I can see where one could lose some fluid.

Cary
Claytor Lake ,VA

On Sat, Jul 22, 2023 at 12:30 PM Brian Ferguson <
brian.a.ferguson76 at gmail.com> wrote:

> I have a freshwater trailer and with a ‘76 Continental so brakes aren’t
> really a thing for me. I actually have electric brakes. I digress. Has
> anyone figured out a way to extend the brake line so air intrusion is not a
> problem? Kodiak makes a 20’ flexible hose extension. Around $45. I’m sure
> there’s a way to engineer something that could coil the line when not in
> use. Just a thought.
>
> On Sat, Jul 22, 2023 at 12:18 PM Jeff Smith Photo <
> jeffsmithphoto at gmail.com>
> wrote:
>
> > Has any one had air introduced in the brake lined by decoupling to extend
> > the tongue?
> >
> > Best Regards
> > Jeff Smith
> > www.http://JeffSmithPhoto.Net
> > 732-236-1368
> >
>