If you frame this in the context of existing outdoor recreation equipment like skis and mountain bikes and then factor in something like FSA/HSA eligibility this is more attainable than I was initially expecting.
Generally speaking, exercise equipment is not eligible. However, one can get a “letter of necessity” from a doctor. I have no idea how hard that would be.
But I believe GP’s point was that if such a thing became eligible for HSA purchase, it would make it much more attainable.
Depending on how much fitment it requires, would be great for a rental. This isn't something that folks that need it for hiking would be using all the time.