I have the same issue, regarding width, and just returned a pair of the Nike waffle racers because they were too narrow.
From experience, although this doesn’t direct apply to track flats, most Nike shoes run narrow, compared to other brands, although I have a pair of Free’s (5.0 Trainer) that are significantly wider and I know that the Nike football boots come with the option to select width.
As Stefanie stated, New Balance historically feature wide toe boxes on all their shoes and, as far as cross trainers and other running shoe models I’ve always found the same with Adidas, Asics, and Puma.
I don’t have as much diverse experience with the various track flats, however.