MakoMart for sure. Everything on that stage is so difficult to work with. I can't ever just secure a kill on it because of its verticality. The zone takes forever to cap, and once one team has possession of it, feel free to say GGs. It's hard to defend the tower because of all of the objects that stick upward that block your shots. Rainmaker is pretty good, ngl, but Clam Blitz is a pure nightmare. Yes, most games are close, but usually the first team to score loses. Even Turf War isn't that fun. I'm more of a Ranked player, but I just can't stand playing MakoMart on anything other than Rainmaker.
I strongly dislike Kelp Dome as well, but rather than Rainmaker, the mode I can stand is Tower Control. Again, taking the zone takes waaaaaay too long. No one really protects you in Rainmaker, and even if they do, people can shoot at you through the grates. Clam Blitz, everyone gets stuck in choke. I'd go through catwalk more, but it's too obvious and people see you way too easily.
One last one. I know this map hasn't been released, so my opinion might change, but I was strongly opposed to seeing Camp Triggerfish make a return. Splat Zones is going to be the same long-range ruled mode it was, you'll never be able to get past 50 in Tower Control, you'll get obliterated in Rainmaker, and who knows what'll happen in Clam Blitz (tbh that's the mode I'll probably favor)? Not to mention, Triggerfish is going to be "Skill Ray" haven. Please nerf the Sting Ray at least a little bit before this map gets released, please.