modelfkeyboards.com is a thing, too. (I'm not a customer, nor associated with them.)
I'm all in on MX-style keyswitches, because you can make keywell keyboards such as the Dactyl Manuform with them. See for example [email protected]. Keywell keyboard design and manufacturing is... shall we say, much more decentralized than Model M keyboard design and manufacturing? :) Many people can make you a curvy keyboard, and there are many varieties, or you can make one yourself, and customize its form as you wish. But this is all far afield from what you actually want, I'm afraid.
Your question also brings to mind beamspring switches such as https://kono.store/blogs/keyboards/silo-beam. Similarly that does not appear to lead to the same kind of experience of clicking a button, paying your money, and getting a pre-existing keyboard removed from a warehouse shelf and shipped to you in a few days, as you would get with Unicomp.