Help: ABS + Shifting = unstable bike

2016 Kawasaki ninja 650 w/ ABS.At the track, as I am going through straights and commencing my hard braking, I've learned to get my downshifts done earlier rather than later. However, since I conduct my hardest braking at the beginning, I normally engage ABS as I am trying to maximize braking pressure. As a result of these two activities, I have had issues where the rear wheel is wiggle as I am downshifting. My ways around this are decrease braking pressure but increases time in the braking zone, or conduct my downshifts later, essentially negating additional engine braking. The later sounds more appealing as I know of professional riders that don't rely on engine braking. However, I want additional input.Thank you! via /r/motorcycles https://www.reddit.com/r/motorcycles/comments/fklysq/help_abs_shifting_unstable_bike/?utm_source=ifttt