For the time available it is an understandable issue, but here' my suggested approach if you're taking the project forward:
The enemies could scale with active pedestals, in two ways, even. First, you could have it be your believed balance "how many pedestals does this boss need to be fair?" The first one is easly a one pedestal, the second one could have 1-2, the last one could have two normal ones and a slow one, I think.
But you could also make the player activate each of them, and the boss becomes stronger based on how many are active (stronger being different patterns, faster attacks, maybe dealing more than 1 damage per blast, more than one HP, one part of it cant be stunned, such things). This way the player can shape their own experience, and you get to design a fight in different balances. One boss can be three bosses if you allow yourself to make it so.
The simple fact you can engage and evolve it in so many ways is proof of how you've developed something good already, just needs to be folded a few more times to show its full potential.