I would prefer to use preventive officiating, and simply have them pick up the patch, or go pick it up myself, and let them know that it isn’t permitted, by rule.
If a member of the kicking team placed the “patch” there, and I didn’t catch it before the kick, I’d warn them (head coach) to not do that again, and report this to my coordinator. I suspect he would then send out a memo to the teams reminding them of this rule, and all future violations would be enforced, without any further warnings. And, I’m sure Redding would pick up on this and remind all teams via a bulletin.
Let’s put this in a different scenario. Very muddy natural grass field. Team A holder brings some sand from the sideline to the field and drops it down, and smooths it for a smooth, dry spot to place the ball. If I see this, I’ll move the snap location a few feet to one side, and kick the sand into the turf, with the same warning procedure as above.
I’ll avoid calling the foul one time. After that, they get penalized.
Robert