Besides the scoring balances, for me, I would like to see that the modes in a ladder, once activated, would either let the player select which mode to play (like the minor villain selection in BM66), or make the mode selection within the ladder randomized.

Either:

a) hit the specific shot to start the ladder, then the player uses the flippers to select a mode within the specific ladder (i.e. like selecting which minor villain mode to play in Batman '66)

b) hit the specific shot to start the ladder, then the the machine/code randomly selects which mode to be played within the specific ladder.

This could open up the game for players to experience variety instead of the Groundhog Day sameness over and over.

I totally understand what you're saying. But a scoring balance fix could adjust the value for each mode depending on what "level" the player is in within the ladder, and progress the points/scoring based on how deep the player gets into the ladder.