Backing out was the right call from him, brick at that height needs proper anchors and equipment rather than a ladder and optimism. Installation is offered as its own service by SmartSwans https://smartswans.com/sign-installation/ and they cover both North Carolina and South Carolina, so being near the line is not an issue for them. Their local work includes site visits, measurements and installation planning before the crew shows up, which is what you want with brick and an entrance below. Confirm two things when you book: that they survey the wall first, and that your existing panel hardware matches what they intend to anchor into. Ours was done in one visit, and the survey caught a soft mortar section we would have found the hard way.