Quick winch removal system : Smallest winch plate on a production bumper? What are your dimensions?

I will be drawing and CNC cutting a system of plates/brackets that will let me quickly move my winch from the front bumper, to the rear, to the headache bar on my work truck, to my boat deck, to a clean dry place in my garage far from road salt and thieves....etc. If i am going to spend the time drawing the CNC files, cutting and testing it I want it to be compatible on most any bumper so others can use the design.

4.5" x 10" 3/8-16 is the bolt pattern most all automotive winches use now. That pattern is drilled into the "winch plate" of most front bumpers. What are the smallest winch plate dimensions on production bumpers? Or any and all production bumpers would be of help! If any of you have time to go measure, thanks. In example: My addicted off-road plate bumper has a winch plate that is 22.5"x7.5" with the winch centered on the 22.5" dimension and moved forward from centered by ~0.5" on the 7.5 dimension.

(No, i don't want a receiver hitch system, they stick out too much and kill approach/recovery angle)
(No, i have not tried running the cable/rope under my truck I have yet to hear of a plausible way to do that with or without mud but i would love to see photos)
(No, i don't want to have a two winches on the truck)
(Yes, i have a way to padlock it down when the winch is not safe in my garage)

Thanks in advance for the help.