I wouldn't worry about it. A lot of starts and planets will need to line up for something big enough to be a problem to get past. You're more likely to pick up road rocks when driving the car then towing. Just avoid the retread alligators or other such stuff that might clear the coach chassis but not the CRV.
That is a bit of a drop for a CRV. I needed a drop hitch for an Accord but when I changed to a CRV this spring no long needed but then my CRV is an 05 with the base plate attachment point above where the bumper frame used to be.
