What if KR Femme had appeared in Rider Time Ryuki?
 

Would she and Ren help free Shinji from Ryuga?

In the beginning of it, she'd still have her grudge towards Asakura/Ouja.

Hope her feelings for Shinji wouldn't be gone.

Aside from getting their actors back, none of the characters in Rider Time Ryuki actually acted in character. I doubt it would've mattered.

Heh. You can blame Inoue on that.

Anyway, at best she'd take the place of Ouja who stumbled into Ryuga and then get beaten by him. Again. Maybe give her a scene with Shinji and Ren a bit while you're are at it.

Eh, Inoue wrote Miho’s only appearance so it may have worked. I’d have loved to see her, but she’d probably just end up dying again.