order of sign-ups to Product waitlists

How do I see who joined a Product waitlist first? We use waitlists for events that we sell in Commerce. When spaces open up at sold-out events (e.g., if people cancel), we want to give priority to the first person on the waitlist. How can I see the order in which people signed up? The list seems to appear in a random order - I tested it by waitlisting five emails for one of our sold-out products, and the waitlist I see on Squarespace isn't in the order in which the emails were added. The 4th email added is at the top of the list, then the 2nd, the 1st, the 3rd, and 5th. It's not in alpha order, either. So how do I figure out who gets priority?

I would like to know about how to do this as well, it's the first thing I wanted to do because that's what a waitlist is (to me at least?) but the fact that there doesn't seem to be a obvious option makes me think that it still needs to be finished?