What's the target audience of the beta program? I'd love to play around with this on a personal domain but I doubt that there will be more than 2 or 3 unique visitors between now and general availability. Do they want signups for the beta program irrespective of the traffic volume of the site or would toy site signups just be more of a hassle for someone to approve?

The verbiage on that page isn't very clear on if there's some manual process for approving beta participants or if it's just grab 100 entries a week out of a Google Sheets page.