I've used my Swaro ATM20-60x65HD spotter for 12 seasons without a cover over the body. I do use a beer can neoprene Koozie over the eye piece as the Swaro factory version falls off in the pack.
The scope looks good yet as it is rubber armored as it comes from Swaro....is your ATC armored? I carry my scope in a separate part of my pack, either the inside tube for the water bladder (hate water bladders) or an outside side pocket on the Kifaru Reckoning. I never put a tripod that isn't cased or any other metal next to it. Wrapping in a shirt or putting it in a wool sock is also an option for the times you need to isolate it.
I once bought a King's Camo case for the Swaro but hated the bulk it added plus the extra weight so never used it.