I run mine direct thread under the hand guard. The Mystic X will rarely cause any issues removing. The Hybrid about 50% of the time requires me to take the hand guard off to get the threaded end cap off.
I’ve never had a problem running a Sparrow under a handguard. I think the suppressor is 5 or 6 inches long and it’s completely covered except for the last 1/2 inch or so. It threads on to a 4.5” 22lr barrel.