Re: 1928 Thompson
Well, not so fast. The Blish lock really does work, though not to the extent originally claimed. First, it is not "two pieces of brass", it is one "H" shaped piece of bronze. When Savage was trying to eliminate it, they found that they had to beef up the rear of the receiver because in the absence of the Blish lock, the bolt recoil momentum was considerably increased and the bolt broke out the rear of the receiver.
Another common Thompson myth is that troops took the Blish lock out of the guns and threw them away. Not true. While the 1921/28 can be modified to eliminate the lock (commonly called the "H block") just throwing it away won't work, as it is the connection between the actuator (the part with the knob) and the bolt.
The Lewis gun cooling jacket also works. The jacket itself does not cool anything, but the way it is designed, the muzzle blast pulls air through the jacket, cooling the barrel. The aircraft guns didn't need the jacket because the motion of the plane through the air provided enough cooling.
As to the .45 ACP, it might not shoot as far as a .22, but subguns are not intended for long range shooting at Camp Perry. And I know the .45 will hit a lot harder than a .22.
Regarding a trigger "fix", though, Muddober is right; with that heavy bolt coming forward, it takes a good solid sear and good engagement to stop it, so any tinkering could easily result in a gun that won't quit, a bad situation.