Okay, so here's my thoughts so far, take them how you will.

-The setup for the story is good. You establish the setting nicely, give the characters motivation, and have it all come together. I liked all of that.

-However, once the growth actually starts, the story starts to falter. The narrative gets very tell-y, and not very show-y. Comparisons to irl things like jumbo jets, and the Richter scale don't work well in the mlp universe. I would instead use natural landmarks and landmasses, things that Zecora would have seen and would be native to her homeland.

-You use 'cock' a lot to refer to male bits, and it starts to feel repetitive when used in succession. I would try to switch it up a bit, make sure you're not using it three or four times in a row.

-This is a subjective thing, but for me, the allure of growth stories comes from a couple things: How it feels to the one experiencing it, the descriptions of the body getting larger, and then the growing creature doing things with their new size. What if Zecora used the fifty foot, giant-dicked Bahamut statue as a sex toy while she was growing? What if when she was REALLY big, she used the hole in the ceiling of the ruins she'd just grown out of as a gloryhole? Things like that.

-Also, it reads better if you use the worded versions of numbers, instead of the numeric (i.e. five thousand instead of 5,000).

Overall, I like this premise better than your first one. It has the potential for a lot of fun, and if you tighten up your writing in the growth sequences, it'll be hot af. Good job, man!

7878573
Thanks for the advice. I'll change the numerical numbers to written numbers and consider changing a few of the 'cocks' to other synonyms.

I'm not usually into this, but there's a first for everything right?

I know I left a rather poor review on your last story. My opinion of that particular piece of writing remains as is but I will not hold it against you.

This is a vast improvement on your original efforts, its certainly more coherent and constructed better so far. I'll let you know more on my impressions when I've read through the available chapters