My first thought was - its massive and would get in the way of almost anything... One nay, one against. Lots of firepower if you can mostly stand still though, it's gotta' count for something there.
I have fired M1 Thompsons at the Keystone indoor Range, outside of Pittsburgh...........
Heavy for sure...............does eat up the ammo....... that drum must weigh 25 lbs.
Aluminum versions of the Thompson were designed, but the war ended...............no reason why aluminum should not have been used in the fist place, but Gen Thompson/Colt did not have access to the alloy back then.