Per the title of this thread I also play a Conn Artist "chest huggin" bell forward euphonium that puts my ear close to the feedback of sound, much as Dizzy preferred. I can't perceive of any rational why a trumpet couldn't also be, but that's not sayin' such has a bonafide technical reason to oppose such. Knowing it to be smaller than my euphonium I can't a problem when seated or standing. Sure be better than making the traditional baritones and euphoniums in a trumpet configuration or even the mellophone. Yeah, when the bursitis and arthritis in the shoulders of the aged act up, playing with a trumpet configuration isn't always a pleasure.