That's not a bad idea.
Here's a couple of mine that never materialized. (Feel free to run with them it you want) They may or may not already exist. I never even checked.
A snowblower that converts to a Rototiller by changing the bolt on front end. I actually designed a tiller that would work with my old Ariens.
A small verticle mill with it's X and Y axis ON TOP of a rotary axis.
Putting a rotary table on a Bgpt type mill limits your rotational capability. You need to move the part on your fixture/vise to change a radius. If you had axis ABOVE the rotation you just move to the new position.
A gun oil that is also a Buck lure.
I get 10%