I don’t have a ton of knowledge in this area, but this seems like it should run afoul of antitrust regulations?

Oh hey, that’s my friend Jackie’s work. Neat seeing it in the wild.

In addition to these general guidelines, there are likely specific building codes in your area for minimum dimensions of stairs. Plenty of homes have non-compliant stairs, but it’ll save you a lot of hassle in the long run if you do things to code.