Looks like I'm the minority here, I'm okay with either for them winning.
In regards to Miya winning, I've been an anime and manga fan since the days of old, so Tsunderes like Miya don't bother me that much. If Miya is unbearable to you guys, you guys will also hate Taiga from Toradora.
The appeal of Tsunderes is that despite being kinda toxic to their love interest, they have this cute and vulnerable side that only the love interest can pull out of them.
Now for Prez, she taps into that childhood/promised love trope. Despite being put into that trope most characters also in trope develop their attraction to the love interest beyond their childhood promise. The older sister is also in this trope, but she isn't that much in the running.