You can go way less on the dwell time. I run 16” Fulton (criterion) with rifle gas. I forget the number but the dwell is like 2” or less. It cycles a lot of ammo just fine. Gas port size matters. Couple that with the fact that you’ll be running a suppressor 100% of the time....dwell ain’t gonna be an issue for you.
the barrel I’m running is not light. I have a PRI tube on it, again not light. Unfortunately I live in a communist no suppressor state, so I have no help for you there.