For this you need an analogue sensing mechanism such as hall-effect sensors (as Wooting use). You can see some open-source reference designs for PCBs, Firmware, and switches using hall-effect sensors on riskable’s github to get you started. Technically you should be able to make a PCB like this and then use the same “switches” that Wooting use, though idk where they source them.

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.