Robbie, within reason (Hell, even beyond reason), there are only two things that limit the amount of negative camber that is available. #1 is the length of the bolts holding the top A frame to the crossmember. #2 is the number of shims available.
Your problem is the guy doing your alignment . Maybe he ran out of shims. I've noticed the guys doing alignment like to pretend there is some mysterious magic, available only to the initiated, required to adjust the front end. Nothing could be farther from the truth.
If all you want is more camber, that can easily be done by you. Using a relatively flat floor and a carpenters square, you can do a good job of getting the sides even. Its all in the number and thickness of the shim pack. If you need more shims, they can be easily made or you can send out a shim SOS.
Bill