Is this enough clearance for the fender?

I recently installed fenders on my road bike, and the front fender was moving and rattling a lot. I assume it’s because only one side has a hole for the fender, whereas in the manual it seems like two are preferred.

To mitigate the issue, I put some foam tape between the tire and the fender. It got rid of the noise completely, but I’m now concerned about the clearance, as the foam lowered the fender a bit. The guidelines for my fender say it has to be at least 6 mm. I stuck a piece of 6.3 mm foam on my tire, and it rubbed against the fender very slightly when I rotated the wheel.

Should I be worried about debris getting stuck and throwing me off the bike or damaging the bike? I don’t have studded tires, so I’m not sure how likely my tires are to pick up rocks or sticks from the road.