By using a greater mass of magnets, placed farther out on the spinning plates, and spinning those plates at a higher speed than is typical, Conifer has managed to use weaker iron-based magnets

The article mentions that these particular iron-based magnets are weaker, but I wonder if they could use iron nitride magnets, which are apparently on par with rare neodymium magnets.

https://en.wikipedia.org/wiki/Iron_nitrides

https://www.nironmagnetics.com/