The primary (first) barrier is routinely constructed a few feet North of the actual border, to provide some right of way for maintenance.
As a practical matter though, I don’t think that squatting next to fence to pop out a few bambinos would actually work for citizenship. Nobody is there to certify your birth certificate.
So you really need more than a videographer and a GPS? Does there legally have to be an "attending physician" or something? That doesn't stop people who are into home-birthing / midwives from obtaining birth certificates. How much would they have to pay a left-leaning certified midwife to walk up to the bars of the wall, look through, and say, "Where do I sign the certificate?"