It does make sense but honestly as much as i absolutely despise Hiyoko's death with a passion, i actually like how her death(unlike every other asshole character in the series, most notablyMiu and Nagito)isn't because of her bad features, its because she wanted to honour Mahiru by tying her kimono, Hiyoko died precisely because she isn't the monster the fanbase presents her as. Not to mention how she died because of her grief(thats three deaths caused by Fuyu's actions, i really wish the game had him acknowledge that). I feel like a Mikan snaps thing just would have been even more detrimental to Hiyoko's character than her dying for being in the wrong place. Though i completely respect your idea