As one of if not the most vocally user of boards in support for Elo and MMR systems. I strongly object to Riots implementation of Duo queing. It generates mismatches left and right because baising it off Tiers and not MM's Class intervals is silly. Yea it wont break the ladder but fk man it can push MM to throw some curveball shitty matches at players.
Easy solution is Duoing is restricted to MMR values and it wont let a class interval gap group. Better solutions removal of duoing completely but I think the features so dam popular that it would be a net negative for the game and Riot that it could impact player participation to the point MM has to widen its range.
A Hard Reset is never preferable. Id love Riot to do it for a preseason just to show the playerbase how much chaos that would make so they wont ask for it anymore.