The first thing to know is that this proposal is strictly neutral and scrupulously fair to all voters, all parties, and all candidates, because it goes right back to the citizens' votes and because it's using only their uncoerced vote, which doesn't exist today. I think the Broadbent report said something like 40% of the votes are strategic votes. Who knows what those people really would have preferred to do?
I did do one number, as an example. With the Green Party having only one elected member, it became fairly easy to figure out. According to the last election, the number of votes that the Green Party got would be the equivalent of about 12 seats, so when Ms. May would vote in Parliament, she would have about 12 seats.
The people who are never representatives would probably have about three-quarters of a seat. They have less than one since they would be overrepresented in Parliament because of the distortions of first past the post, which of course would not exist in the system I'm proposing.