Measuring carefully still left the fronts just a little misaligned. Here's my approach to getting the left and right sides to hit the stops evenly.
This drawer could be pushed in about .050" on the left side after the right side was home.
Aligning Drawers.jpg
3 shims 1/64" thick between the clamp (used as a stop) and the slide, made the move precise. They were removed and the slide was slid forward and retightened.
Adjusting Drawer.jpg
Similar for vertical adjustments.