I mean, mistaken identity wouldn't work, becasue we already saw Sugu doesn't care at all for a bigger dick with more stamina and is literally unable to get off now if she doesn't imagine she's fucking her Onii-chan, that was the whole point of her using that 'illusion dust' on the council guy/Silica's dad when she used sex to get that time skill from him (And even then she literally was able to stay sane enough through sex to not say "I love you" because she KNEW it wasn't actually Kirito despite his looks, which is something you never see of a girl in a NTR game that has been 'corrupted', so it really shows how unique her character is). Drugging her could be an option, but again the same result stands, she literally doesn't care for "better" sex if it's not with her Onii-chan so she basically would recover from the aphordisiac, then have Sinon get the council people to kill Inoda, which is why that can't happen either, Inoda immediately bad ends in any way that isn't her wanting to fuck him 'wilingly', which would only be with the council's brainwashing XP
Also, as someone who knows Kirito never would be a bitch cuck normally and doesn't care much for NTR cliches, I like the Gigachad route twist a lot, especially as it can also be seen as a setup for how far Administrato's BS can get which we're no doubt gonna be seeing in the endgame of either route, but yeah, there is a reason why Fujino allowed the route split for people who wanna see one outcome or the other, or just wanna see different options of hentai after all :3 (Plus, as far as the route split so far seemed, Kirito will still lose Asuna no matter what anyway and Inoda won't face any consequences for it in either route)