I have a suggestion about rematch/no rematch voting.
As I understand glicko2 sets an expectation of who is going to win the match. Sometimes it is less certain of the outcome, sometimes more (based on rating difference). The goal is to encourage uncertain (even/balanced) games. My suggestion is to check/uncheck the 'rematch' vote box based on how well the match outcome conformed to expectation.
If it was a stomp by high mmr against low mmr, make the rematch box unticked by default to put players back into queue and hopefully find a better match for both teams.
If the MMR delta between the two teams got smaller (unexpected outcome), then tick the rematch box by default because that was an uncertain game.
Since most people probably don't bother voting one way or another, this would subtly encourage more balanced games more often. Can muse maybe provide some data maybe on how many people vote either way, vs how many abstain?