The process apparently "just works" for some folks, but I had already deleted the license so the link to certify individual use just gave me the error, "Something went wrong."

I added a license (setup billing) so I could ask support. There was a link in the robot support chat, something like, "Questions about legacy G Suite (may have included the word 'individual')" which walked me through a wizzard to certify that use was individual non-business only, but it required downgrading license to 'Google Worspace Business Starter'.

The option to downgrade to Business Starter was not present. I had to remove the license again (this is supposed to delete all user email, but I had already done this when originally removing the license). After deleting license, the option for subscribing to Business Starter was available. Everything went smoothly after that point.

I'm personally going the self-host route, but this will allow me to send outbound mail using google as smarthost, and have the mail be delivered to inboxes instead of spam folders.