Someone broke this down in /nfl subs, would have been an interesting test for the coaches
A. Kneel on 3rd down, run the FG team out with a running clock (but now with 15 seconds more urgency)
B. Deliberately throw the ball out of bounds then kick the FG on 4th down with ~16 seconds left. Runs the risk of a penalty if the Bills try to do anything too fancy.
C. Bills play it safe and kick thr FG on 3rd down with 19 seconds left
Also I wonder before that, does keon have the smarts to just fall down there if he doesn't get get tripped up he looked like he wanted to walk in badly