I found this amazing TF artist on Twitter that not only specializes in tail growth TFs they also have TFs that involved the kind of TF Romance I was looking for. I'll eventually post their tail growth animations in the official Tail Growth Thread but until then here's a link to their twitter page:
https://mobile.twitter.com/doldolphin_r18
and I think this is their pixiv page:
https://www.pixiv.net/en/users/4514076/artworks
You need an account to see it though, maybe.