You could try using different exercises for H/L/M days.
Some lifts or moves are just more suited for different purposes. Trying to make 1 lift do everything is not a great idea. If you believe in muscles fibers, you can't believe 1 exercise gets them all.
Try some kind of barbell press on heavy, lower rep days. Like for strength. Big lifts should be a part of your program.
Dips are perfect for light day. The resistance is light enough that you can focus the work on your chest or tris, without blowing out your shoulders or elbow. Calesthenics, or moves where you push your body through space should be part of your routine.
Hitting the angles in between, on medium day, with moderate weights and moderate reps, using dumbbells, seems like a no brainer to me.
Marvin Eder was strong at every lift and every move, from every angle, with any apparatus. Dude was great at dips, AND everything else.