I don't know what the O.D. of the EZ-LOK is relative to the 9mm CAM-LOK which is what I use for several .22LR applications. My concern is that the uncovered muzzle/barrel adapter threads chew the inner lining on gun cases, not the risk of damage to the adapter threads. I have asked Griffin Armament if they would make and sell push on, friction fit thread covers similar to the plastic flash hider cover that is used, primarily by the military, on the M16 A1 and A2 flash hiders, but did not receive a reply. Push on, plastic covers are also commonplace on the threaded pipe one encounters at hardware stores.
I have made my own expedient version using old, exhausted large felt tip marker pen bodies. One could probably do a 3D printed version rather easily. Threads could be included, if desired, but my own use has not shown the need for threads thus far as the fit is sufficiently snug.
Best of luck.
MHO, YMMV, etc. Be well.