I ALWAYS use a coil cover. You don't want rocks and sand to wear out your coil. Since they are hard wired it is an expensive repair since you have to send it in. NOT just the cost of the coil but down time and labor cost with that.
I also have my name and phone number etched inside the cover. IF my machines get stolen, hopefully if they ever go in for repair, the good folks at First Texas will know they are mine.
Plasti-Dip is amazing....put on several coats as you want it thick. One, two or three coats won't do the job. The more the better.
I run my coil over reef and rocks and it just softly bounces off.
CZ coil covers are a nightmare......goes on as one piece but comes off in many as it jams on. I needed side cutters to cut mine away...never again !
Also dries very fast between coats.