There can be corruption and romance at the same time but it's only for a decision that Miyoko will make (I mean, there will be parts of the game where you play as Miyoko). If you force Miyoko to share her body, that will be possible only in evil path.I have question about this though, in the corruption route will there still be a chance to have a somewhat romantic relationship with her while also whoring her out (if you choose to whore her) or will it be all just her being your slave basically. Will it also be purely sharing (or netorase basically) or will there be other elements of netorare?
But more content for corruption depends on Patreon support. A lot of art would be needed. :/