There are many options for how to mount a RAM ball: https://rammount.com/collections/ball-bases-b-size
And so they conform to various standard thread size/pitches, so it may just be whatever works best for your design. For the threaded ram balls, I assume there would be a recessed hex nut that...
I think it would be great if you could offer a mount that doesn't have the ball and just a surface to screw or bolt a ram mount ball adapter to.
Once you have that, its easy to install something like:
https://rammount.com/products/ram-b-237u
or
https://rammount.com/products/RAM-B-238U
And...