"premier" Highwayman vs 1930s Maxwell
(premier on top, maxwell underneath)
I got my "premier" highwayman with the same shoulder (frame) size as my maxwell. In theory they would hang the same on my frame, but in reality there are some differences. The premier has slightly narrower sleeves I think, I would have to double check that when I get home. The premier sleeves goes into the bodice at an wider angle, this helps with the mobility on slimmer jackets. I think this is a plus for the premier cutting. However, the premier cutting is based on pre war patterns and they are smaller jackets with slimmer neck width and narrow sleeves. If you are already feeling too narrow on your Maxwell, the premier is even narrower.
"premier" highwayman vs "50s regular" highwayman
"30s" Maxwell vs "50s regular" highwayman
the 50s cut is similar to your 30s maxwell at the neck line, nice wide and comfortable. And it has wider sleeves than the maxwell and wider torso at the same shoulder size. That's why I originally suggest looking at a 50s Teamster, assuming it is built with the same features as the 50s highwayman. It's got the action pleats like your custom maxwell, but wider torso and wider sleeves for you to easily wear a mid layer underneath. But I don't know what the neck line is on the Teamster, you'd need to find that out yourself, is it same as Highwayman or premier I don't know.
The most athletic / beefy body build pattern from Aero is actually their Type 3 trucker jacket. It has the biggest sleeves, and shoulders, paired with slim body and comfortable wide neck line. The beefy sleeves also goes into the bodice like the Trojan jackets, even wider than the premier jackets, making greatest mobility. I don't know if they build a half belt on this pattern block though. This is really the best fitting /mobility pattern for athletic husky gents.