1. Move sumore to either kicking or striking and add swfixed instead to take its place in grappling. I don't know if people want to keep sumore in general just based on what I've heard, though personally I don't like it either.
2. Have 5 mods for each group if it's a BO3 and have both players veto 1 mod. Lots of competitive games have the ban system like League of Legends with 3 champion bans per team, Starcraft with map vetos, Hearthstone (in competitive) with deck bans, and CS:GO (in competitive) with map vetos. If it's going to be a BO5 in the future then have 7 mods total to choose from instead.
3. Placement matches would also be good. It's healthier to have your first few games be really swingy with MMR/elo because it prevents the really good players who are starting ranked out from having to play against complete beginners. It also prevents them from having to grind really hard just because they need to play through an elo bracket they don't belong in.
So for example if you win your first 10 sets then you should gain way more elo from those 10 than if you go 5/5 in placements and THEN win 10 games.
4. Make elo more swingy in general as well. Winning one set of games (after placements) should be worth like 10 or so elo instead of the 1/2/3 it is now, and placements at like ~30 each. Right now basically everyone I've seen in the last couple years with a rating has been between a 100 elo range which shouldn't be the case because there's barely a noticeable difference in ratings from one player to another. League of Legends for example had the default be 1200 elo, placement games around 50 and each win/loss was worth around 17-20 elo which worked really well. Pros were 2200-2400, above average people around 1400-1900, and the general population was placed 1100-1300. As of right now I'd guess only a handful of people would even break 1700 when the starting point is 1600, which is barely any difference at all.
5. Lastly, in my opinion there should be a match history, leaderboard and win/loss record somewhere. I doubt that would be implemented into the actual game itself so I guess somewhere on your profile here on the website.