I don't understand why it would reduce self-voting. The hypothetical self-voter gets either 25/75 =100 or 50/50=100.
Are people expecting, oh, but then someone could snipe some of the curation rewards from the whale by pre-voting them?
But they're still delivering as much author value to the whale as they're taking in curation... so it's a zero-sum improvement. Why would this change self-voting behavior?
A self-voter gets the same amount under either system, but a non self-voter gets more under 50/50. So the incentive to just self-vote instead of "voting your true opinion" is much lower. The 50/50 division will also impact the direct profitability of buying votes from bidbots (bidbots won't be able to give us as much money to a post relative to their SP by voting on it).