For new endings, new routes are required, what about these:
There is cosplay store, but Ryo still can't dress as catgirl! Dresses of catgirl, succubus, foxgirl, cowgirl with paw gloves and stockings, cat ears headpiece, tail buttplugs, thematic toys (dog and horse dildos), room with petplay interest.
Hucow room, accessed only with lactation, crosses with cowgirl cosplay, milk pumps for nipples, thick nipple rings, cute cow horns, cow print outfits.
Old rich fan romance option, fetish cow (MC lives at fan's house and he likes to watch how Ryo milked by powerful machine) and happy cow (they marry and fan milks Ryo manually everyday) endings.
Submission room, leather harness, BDSM clothes, ballgags, latex bodysuits, not allowed to enter without chastity cage (not My thing but fits the theme).
Dom romance option, key (MC gives him key from chastity and becomes his sub) and stepford wife (MC becomes perfect beautiful obedient housewife) endings.
I wrote about headdresses, it probably would be pain in the ass to add but what You think of head clothes slot? For fake ears, horns, ball gags, latex masks.
Also what about neck options? chokers, collars with words "bimbo" or "slut" written on them, bell collar for a cow.
This can be too big, what if add option of seeing back view? Not the whole body but closeup without clothes of Ryo bending and spreading his buttcheeks?
This will give reason to buy new different toys, also stat of how his backdoor stretched, Ryo can "train" it by wearing or using toys of bigger size for certain amount of days.
And it can lead to accessing "size queen" room, where only huge toys allowed.
I already wrote about it, but for natural breast growth route, when Ryo doesn't want to get implants, one of fans offers to use new hormonal injections, and after it Ryo shocked seeing he started to lactate, discovering it was illegal bovine hormones.
Also excessive use of such drugs can lead to nipples becoming longer and thicker. I love cowgirls and lactation, don't judge Me.
Sorry for writing too much, the last thing, nipple pasties of star, heart, cross shapes, fishnet stockings for legs and fishnet top.