My thought was if this would be able to be controlled on a regular MX switch and if such a program already exists?

No. Most MX switches feature a mechanical switch that moves actual metal pieces to complete a physical circuit by coming into contact with each other at the actuation point. It has neither the ability to detect where in the keystroke it is nor alter the point at which the metal pieces make contact.

I say “most” because there is a thing called an “optical switch” which can have this type of capability, and they DO make this in an MX form factor, but you can’t just use these in any MX compatable board, it would need to be a board designed to work with optical MX switches.

How much of this was soldered by you vs the pcb manufacture? Boards without a separate MCU have always fascinated me, but I haven’t been able to price one out because haven’t been able to figure out how to use JLBPCP’s pcb assembly service.

Functional as in it technically works or that its comfortable and realistic to use?

Mx spacing is 19.05mmx19.05mm. Choc spacing is typically 18mmx17mm. And this is 16.5mmx16.5mm? Maybe its just your hands but those appear even smaller than that.