Maybe I missed it somewhere, but I'm wondering why using a (micro) fly-cutter hasn't been mentioned.
The only micro fly cutter I know of that a Nomad can use is unsharpened. Most people cannot sharpen one themselves (it is still taught in machining school but sharpening is rarely used now a days. Sadly, this has become a specialty) and machine shops charge a fortune since there is no initial sharpening. I investigated this - including getting quotes - and was disappointed.
Fly cutters put considerable forces on a spindle due to their asymmetric design. I'm shy to try, at any expense, with a spindle as small as the Nomad. That said, they produce some of the best surface finishes possible. I would argue even better than a face mill... and a HUGE amount cheaper too!
They rarely come with shanks less than 5/8" and only the unsharpened one at 0.125" could be found. If there is one out there with a 0.25" shank, please let me know.
Yes, I know how to make one. I would need some Tormach time and I've been crazy busy.
HEY! Maybe we can get @Randy to go into the Nomad 0.25" shank face cutter business (he has a Tormach)!
There are spoiler board tools. Those are the ones that are from 1" up to 4". I have one of the smallest - certainly not micro - one and the Nomad is "so so" driving it. The spindle just doesn't much power/torque, the tool has considerable mass and moment of inertia, and the results were not acceptable to me.
I haven't had the time to do a proper evaluation and report the results. There may be a good soultion that produces good results but my initial experiments did not go well. I can say that I suspect a good outcome is possible. If people really want this I can shelve what I'm doing and try things out.
When small, they aren't expensive... but they have to work. An SO3 could easily use a 2.5" one with no problem.
I have an Amana Tool RC-2243 spoiler board tool. Amana is a known, quality tool provider. The knives are even replicable. It requires a 0.25" collet.
Also, anyone using a spoiler board tool better have a dust head, a dust separator, and a dust collector. if the exhaust air is dumps where humans are there better be a 0.3 micron HEPA filter. The dust and particles generated by these tools is... insane... and they are done really fast too (when they work).