Thanks, Steve.
I don't want to throw you off course too much; you already have enough work cut out for you, as it were, so no need to fret too much about CH Products' compatibility. CH Products hats cannot be modded as easily as TM controllers; the hat and stem are a one piece construction.
I have to admit I prefer the feel of CH Products 4 switches; the tension is lower than on older TM switches, but is still solid nonetheless.
My suggestion; leave the drilling to any potential CH Product modders for a limited number of hats and see from there how the demand for that goes.
Apart from a number of hats to rejuvenate an old FLCS, I'd be interested in getting a few hats that aren't drilled so I could see how difficult it would be to mod CH gear with. Maybe with a few threaded standoffs...! I will have to look into that.
On a side note, and if it doesn't violate any trade secrets, I'd love to know how you go about your manufacturing process.
Thanks again, Steve. And good luck!