I have opened one personal account and accounts for each of two LLCs I have. I got 42k miles and a partner got 21k. It's been 21k forever, so I don't think I'd hold out for 4k more. They did post surprisingly quickly.

They don't allow churning from what I can tell, but any person/entity with their own SSN/EIN can open an account. Theoretically, you could start an LLC, get an EIN, and open an account for that.