Another way to do it is instead of averaging out the votes, say 5 votes: 0 + 0 + 1.35% + 2.7% + 2.7% = +1.35% increase.

You could do the option with the most votes wins. As that way miners who are signaling +2.7% are not getting their higher investment diluted down as long as they have consensus. Once the threshold is reached all miners would drop down to not voting until the next round.