At some point, he had written HD Sports (Wilson/MK) asking them why they haven't switched to stainless steel (which he prefers). All he got back was a long letter extolling the virtues of plain carbon steel.
You don't happen to know what those virtues are?
E.g., Is it possible that "silver soldering", and other forms of welding, work better or are easier on non-stainless steels?
Or is it possible that it is easier or or more reliable to nickel and chrome plate non-stainless steels than stainless steels, or that the engraving looks better?
Is it possible that the metallurgists at MK and Wilson are simply more familiar with the non-stainless steels, and know more about tempering and hardening them.
I admit I love (high carbon) stainless steel blades. My plain high carbon blades needed sharpening more often, in my personal use. And they needed more care. I rarely bother to oil or grease my stainless blades. As best I understand it, high end figure skating blades of both types are sharpened to about the same "hardness" (i.e., resistance to deformation) - i.e., the main blade is tempered to a Rockwell C hardness of about 30 or 40, and the edge is re-hardened to about 60, according to some sources. My impression is that the latter that is fairly close to the limits of how hard those stainless alloys can be hardened, whereas conventional high carbon steels can be made much harder.
But a lot of people in the high end knife community prefer plain high carbon steel. There must be some advantages that I am unaware of.
The most rust-resistant stainless steels, which are not very "high carbon", like some of the marine grade alloys, cannot be made very hard, and would probably be a bad idea for figure skates, unless you skate on ice with lots of salt or other corrosive components.
(I've also been told that some people in the hockey community prefer softer steel blades. They need to be sharpened much more often, but apparently, being less brittle, they can be made more sharp to begin with. Perhaps they are also more durable under the tough treatment hockey players give them?)
This may be a completely crazy suggestion, but could it be that HD Sports uses plain high carbon steels because they are cheaper? Also, because even the high carbon stainless steels are being hardened close to their limits on high end blades, maybe you have to do the metallurgy much more carefully - which would also affect production cost. The claims that have been made that they have less than ideal quality control, even on their most expensive blades, suggests that they are quite production-cost conscious.
Anyway, this has little to do, AFAIK, with sharpeners. AFAIK, all the major brands of sharpener can deal with both stainless and non-stainless steels.
That said, I spoke to a coach who skated a lot on artificial ice, which rapidly wore down blades. She said that she and others there used inexpensive blades to save on costs. I think that if I wanted to experiment a lot with blade shapes, I would do the same thing. I would start by measuring the shape of the high end blades, and copy that shape to the cheap blades (though copying toe pick shape would be pretty hard). Since the Sparx isn't designed to alter rocker profiles, I would choose one of the other types. I might even choose a machine that was designed to follow a template, such as another blade. Some of them can - I'm not sure which.
You have probably already found these and other training resources:
https://geppettosskateshop.com/skate-tech-training https://www.amazon.com/John-Harmata/e/B00DRDZ930/ref=dp_byline_cont_book_1 (same teacher as the one above; the book is light on technical sharpening details).
http://www.iceskateology.com/Skateology/Skateology_Manual.html http://www.pro-filer.com/training http://blademaster.com/web/usa/en/content/32-documentation-downloads http://blademaster.com/web/usa/en/content/33-videos https://www.youtube.com/user/BlademasterGuspro/videos