itch.io

I was thinking, and I think this would be a good progression until you get to late game hyper sizes:
-36-80 inches; expanded progression from an AA cup to a ZZ or ZZZ cup, two inches for each major cup size increase (A to B, B to C, etc) and for every inch you could either hit a sister size (D cup to DD, H to HH, etc) or get an update with your increase. The current 26 descriptions are all good with only one or two exceptions, so adding a line or two to the end could work for the one inch updates, ie "DD cup? E cup? Not sure what size, but you definitely need it [... well, maybe more like an EE cup really}

-80 to 100: that can be kept as is if you want to limit the number of additional descriptions you're adding, but you could give one extra at 90 inches to imply a difference in size between beachball size and yoga ball, like, at 90 inches "Well, you went to the beach and the funniest thing happened, you held up a beachball to compare to your breasts and it turns out each boob is now way bigger these days! That might explain all the glances you're getting from your recent growth..."

-100 to 500: the spacing here is descriptive but kind of sparse, an update at every 20 to 25 inches would be nice, even if its just mentioning things like "Well, you almost got stuck in the doorway today, so #goals met!" or "Your friend is incredulous that they look even bigger when you bounced up to them today. Maybe its your boob greed speaking, but that sounds like a challenge to you!"

-500 to 1000: depending on how fast you intend for these intervals to go, every 50 to 100 inches works, keeping your hyper theming (bigger then a garage, a car, a single story house, etc)

All and all that should give a good progression to the early game into early hyper sizes and from there you're probably growing fast enough it can be spaced out every 100 inches or more