They will. I used plot saver one year before I was willing to pony up for a Gallagher-style E-fence. The results looked great at first. I only used it on about 1/4 acre of the 3 acres I planted. Deer just hammered everything out side the fence and avoided the fenced area. I religiously applied the deterrent mix each week with a sponge. However, once deer had wiped out all the beans outside the fenced area, the beans inside the area became more and more attractive on a relative basis. Before long, they were breaking into the fenced area. In the end, you could not tell any difference in the beans inside and outside the fence.
Bottom Line: Deer do perceive the fence as a risk and if they have the same food nearby in an area they perceive as lower risk, they will eat that first. However, if that source dries up due to browse pressure (or anything else), it won't take deer long to start breaking in to the fenced area. Once they do, they learn quickly the fence is not a threat.
You method will determine which beans the deer eat last. If you have enough beans outside the fenced area the beans inside may canopy and flower.
The first place I would put my money is into RR forage beans in a case where browse pressure is a major factor, not a minimally deterring fence. I have found that it takes very little browse pressure to kill ag beans. However when I used Eagle beans, deer would keep them naked all summer, but they couldn't kill them. The beans would grow new leaves just about as fast as the deer ate them. I kept upping the acreage of beans planted and when I hit about 7 acres in my area, they would canopy, flower, and produce pods.
The downside of this approach for folks up north is that much more of the energy of forage beans go to leave production rather than pod production. Therefore the pods and beans in the pods are smaller. Forage beans are generally indeterminate and will mature very late. None of this is good for a late season food source.
Another strategy I've seen used is to plant the interior of the field with ag beans and plant forage beans in the perimeter. Deer generally feed from the outside in. This can give the ag beans some protection, again, provided you have sufficient acreage given your browse pressure.
Thanks,
Jack