In my years of assisting with skate sharpening, any non-leather material stinks to high heaven if not taken proper care of. Padding in the boots, the material the boots are made out of, the socks stuffed into the toes to wear again... Yes, your hockey boots will hold more funk than a leather skating boot.
There are, BTW, a variety of rules about the size and nature of markings on blades at the ISU website. I'm not sure to what extent local USFS approved competitions (or Skate Usa competitions) have to conform to ISU rules. I don't know if all hockey blades conform. But I wasn't thinking of using hockey blades for figure skating - just hockey boots.
There are a bunch of products and procedures advertised to prevent or reduce boot odor, e.g.,
https://thorogoodusa.com/how-to-keep-work-boots-from-stinking (note they suggest treating the feet as well as the boots),
https://www.reddit.com/r/Boots/comments/16ow4qr/work_boot_stink_tried_everything/?rdt=54974 (someone suggested vodka!),
https://www.quora.com/How-do-I-get-a-bad-stink-out-of-a-pair-of-boots, standard antiperspirants and deodorants (or both), ozone, fungicides, etc.
Do you know if any of them work well for everyone?
I don't understand why leather would stink less than plastic and plastic/fiber composites, since I would think it would absorb sweat more.
If it's because leather makers add "tanning" chemicals like chromium sulfate to leather so it doesn't rapidly decompose, that ought to be possible for non-leather materials too. If it's because leather breathes, which helps get rid of sweat, I'm not sure how true that is of high level figure skating boots, which have stiffening layers. Anyway, many socks wick sweat away.
I've never noticed much of a smell on my skate boots (which admittedly are leather), hockey and speed skating boots (both of which I only used a little), hiking boots (also leather), ski boots, or tennis shoes - but my sense of smell isn't all that great, and my feet don't sweat much. But maybe if I used hockey boots a lot the problem would be worse.