Okay last one, third thought is that I wonder what the psychological effect on whales will be when they come in to gift a post with a high powered vote which now has no effect. The UIs will need to be updated, but if a new vote is the highest vote the estimated payout would not change!
Assuming the post had 2 or more other voters, the estimated payout would still change, but the new value would be based on the value from the previous highest voter, so yeah - it would be a very different experience.
Maybe there's not really much of a point in removing the lowest value vote in this context. If you remove just the highest, it might work out to be something like a second-price auction. I don't know much about them, except that they're used for digital advertising by Google and others. However, according to this link:
The theoretical nicety of second price auctions, first pointed out by William Vickrey, is that bidding one's true value is a dominant strategy.