I did an upgrade to a 70w BLDC motor, tutorial and results here: Nomad spindle motor....upgrade?
Honestly it wasn’t worth the trouble.
Vince’s mod was for a shapeoko, not a nomad. There would be some pretty significant changes required to get a router to fit and be usable. Likely you’re building a whole new machine at that point.
An AC spindle like the ones you show it simply not going to fit without even larger changes, and frankly at that point you are basically building a whole new machine. I’ve found that since I’ve gotten my SO3 and gotten it tuned and squared well, I rarely use my nomad. My nomad is a little accurate (screws vs belts), but not enough to be impactful for most of my projects.