Alva baby pocket diapers SIZING (30 lb toddler)

I am looking to buy some new pocket diapers. We currently use Norah’s nursery and bum genius (the bum genius were passed down in great shape except the elastic is now dying and I don’t want to replace it). Our 21 month old fits fine in both brands with plenty of room for extension on both the vertical and rise snaps. She is 31 lbs.

Does Alva baby pocket diapers only fit up to 36 lbs? Does anyone have any experience or insight on this? Does anyone know if they are comparable to BG or Norah’s nursery in terms of measurements and fit? I have big kids and thinking she will definitely put on some more pounds before she is potty trained.

Thanks, my fellow cloth mamas!