I don't think there will be any problem, but how big is the rock?, and did you position it right over where your head will be??????
I've noticed the zippers used on blinds aren't always the greatest of quality. I had to do some serious lubrication on one zipper on the brand new blind I bought this year. It de-railed the first time I tried to zip it up, but some bowstring wax (it was handy
Now don't forget to remove the poles before you try to fold the blind.
BTW - my old blind has real "character". One door sewed shut with bowstring material laced over the zipper, and one pole duct taped together!