OK to leave trailer brake applied without a trailer?

Our company's trucks ignore outside air on the premise that the "interior comfort" feature suffices to keep drivers cool in the desert heat, which I don't have a problem with during the day, but it wakes me up during the night every time the cab shakes due to startup/shutdown.

 

Yeah I forgot about all the implications of leaving the hose unhooked indefinitely. It never happens in real life because whenever you forget that it's unhooked and release the brake, it takes very little time to notice something's amiss so you jump out and hook up the hose pronto.

A plugged glad hand will be one of my most-prized possessions if/when I ever need to park overnight in Phoenix in the summer while driving for this company.