AUG41, thanks for posting this link. I don't think Williams has done a good job about marketing this sight. It may be perfect for my Mini-Thirty. I have an ACRO on my 3 Plus.
I don't understand the fascination / obsession with co-witnessing optics with BUIS. The viewing window is so small on red dot / holographic sights co-witnessing blocks the view. Just mount the optic on a lever actuated attaching mount and if the optic fails just remove it.