If Oda wants us to believe Mihawk is indeed the strongest swordsman then there's no reason to give Imu an exception when he's using swords and sword attacks. In that regard, Mihawk should still be supreme. Not sure what's disingenuous about that, no one said Mihawk is stronger than Imu in anything outside of swords.
Funnily enough, this is actually starting to sound similar to when the likes of Erkan talk about "pure sword skill only" and use that to downplay Mihawk while excluding a whole host of other characters from being swordsmen (e.g. like Law and Linlin) because their swordsmanship is tainted by devil fruit usage and thus aren't true swordsmen and don't come under the remit of Mihawk's title.
Look man, there are basically three main paths to interpret Mihawk post-Imu now:
1) Disciple of Erkan: Mihawk's title is World's Greatest Swordsman meaning he is the most skilled wielder of a blade, not the strongest. Anyone that uses a blade in combination with anything else like devil fruits (e.g. Law and Linlin), demonic shenanigans (Imu) or even just advanced Haki (e.g. Shanks, feckin somehow) don't count as swordsmen. Sword wielders and swordsmen aren't the same and Oda made a distinct difference if you autistically micro analyse words while ignoring context. All consistent followers of this train of logic will downplay Mihawk in general and will obviously consider Imu to be superior to him.
2) Scholar of Average Interpretations: Mihawk is the World's Strongest Swordsman, stronger than any other
known sword wielder on the planet, regardless of other factors (e.g. devil fruit and Haki). Swordsmen and sword wielders are the same since Oda clearly isn't bothered about niggling dross like that. Imu is obviously a completely
unknown individual to the world of One Piece, thus Mihawk's title can't be used to put him above Imu anymore than Kaido's now obviously defunct title or Whitebeard's equally defunct title can be used against Imu. Imu is probably stronger than Mihawk.
3) Acolyte of Nik: Any character that wields a sword, past or present, is automatically inferior to Mihawk due to his absolute omnipresent title that is a fundamental rule of reality within the world of One Piece. Imu uses a sword for his best attacks. Sword wielders and swordsmen are the same because Mihawk, Ryuma and Zoro are clearly Oda's favourite characters. Imu is a swordsman. Mihawk >>> Imu. GG Imu.