The display holder could have a ledge at the bottom. And if you're selling the mount, sell the blinders/shroud too, and integrate it into the top frame. The way those things are attached to displays is always so flakey -- Velcro and such. Their failure is your opportunity!
And use plastic thumb nuts at all the pivot/tightening points to make it easy to adjust in the field (also fold up for transport). If you add interlocking geared "washers" at the main pivot point, it will be more stable with less tightening and force on the nut and thread.