It feels like the primary dynamic I've seen of Momoka x Nina in doujins is Momoka running away from her feelings and Nina aggressively chasing her which, to be fair, is lore accurate but I do find it amusing none-the-less.

Here I was thinking I’d get a doujin where Momoka is the top.

is it gone?

yes: https://dynasty-scans.com/forum/topics/23547-hamchan69-discussion