This thread reminded me that I'd seen something about a new design for rollers five years ago, so I did a search.

Crown rollers were introduced at a bike show back around 2018. "Crown" refers to the roller design; they're largest in diameter in the center of each roller and smallest in diameter at the ends. Seems counter-intuitive, right? But apparently, that's how rollers for belts used in industrial applications are shaped, to ensure that the belts stay centered.

Incidentally, the design also places the rear rollers a bit higher than the front, so the bike is level instead of having the front wheel elevated, as in all other roller designs.

Just looked around for updated info. The company did a Kickstarter campaign, but I can't find any evidence that the rollers ever shipped or that the company is still in business. (There's a Facebook page link for Crown Rollers, but I don't do Facebook.)