With the step file I see it is pretty easy to add or subtract various faces and what not. Is that kinda the idea? It allows me to treat it like a perfectly faced regular object or is there some kind of interface for tweaking the size outside of this?

This took me down quite a rabbit hole. Unfortunately it does not look like the free version of F360 will allow you to make changes as intended. I've updated the model to include the .sldprt file. This is the part format that Solidworks uses. It is unfortunately not used natively in F360 on free accounts. There are 'maker' accounts for Solidworks that you could try. This design is supposed to allow you to change all the critical dimensions of the triglide by simply updating variable.

Dang man. That's kind of a relief to hear honestly. I actually have the Maker version of Solidworks so let me give that a try. Would the original step file have let me make changes or is that what the sldprt file does? I really appreciate you digging into this!