From the research I have done pistol length gas is the best all around system to run, for suppressed or un-suppressed with the 300 BO. I currently have a 16" 300 BO with pistol length gas that runs great with a can, I have on order parts to build a 10.5" 300 BO. My plan was to run the pistol length gas system but if I get trouble I will replace the fixed gas block with an adjustable one. As for dwell time I don't think the amount of gas has to much to do with it, it's all about the timing, if the casing isn't ready to be extracted more gas isn't going to help.
Some good info in this thread.....
https://www.ar15.com/forums/ar-15/-3...--/121-705771/