Not sure what that’s about - I guess since it’s not easy to shrink a volume, you wouldn’t want to needlessly extend it in the first place. Hence adding just a little more space as as required. But if you do require e.g. an extra 200 GB, there’s no point in doing 20x +10 GB.
Anyway, with large total volume sizes you might be running into LVM problems on your storage hardware, which Btrfs seems to fix for some people in the ticket.