I'm quite confident that if the outcome of this new feature will not serve the steemit purpose (reducing the influence of bots, rewarding the long tail of content), you'll keep tweaking it, as you have done so far and as any entrepreneurs do.
Here is my little proposition though: Discrete target vote distribution. As the voting power of minions has much less impact than the one of whales, as the majority of users are minions and as you need to maintain the activity of the minions (who are your early adopters):
I think adapting the target vote (and/or the regeneration days) according to the steem power of each users could contribute to a good equilibrium without arming the user engagement (example of target vote distribution: 40 for minions, 30 for bigfishs, 10 for orcas, 5 for whales) It may not contribute to dimish drastically the influence of bots as your initial feature will, though