^^^ That gas tube protrusion is fine, and will not hinder your BCG travel, at all. That's what we usually end up with on "the half-way barrels" on the gas port location. AR-15 gas tubes are too short, and don't meet the minimum, but the AR-10 Carbine gas tube pushes it just past the midway point in the cam pin cutout - better than being too short, and it doesn't cause any issues with function. Maybe you have a little LONGER unlocking time, instead of a SHORT unlocking time - but it's better for a gas gun to have the longer time, vs. the early attempt at unlocking, from a short gas tube.
This was your reply so I am going with your "Longer will be ok, shorter will be issues" answer. That was easy, thanks.