(Everything in this post is coming from someone who primarily plays 128 player breakthrough)
Vehicles - I don't think vehicles are as much of an issue as people make them out to be. The way that the game is supposed to be IMO is that if I am in a vehicle vs a player on foot, I should have the advantage. It just makes sense. With that being said, I think that the number of vehicles for the attacking team should be reduced. If not overall then at least toward the end (in the last sector or 2). Specifically Air vehicles and transport ground vehicles. A few tanks is okay, but when the defending team is being swarmed by 4 helis and 6 boltes it tends to not feel fair. Perhaps make it so that each team can only have a certain number of each individual vehicle. Like if there are already 2 people using a bolte, then if you want a transport vehicle you need to get an LATV instead. Also another approach could be implementing things into the map that prevent vehicles from being able to view/reach certain areas.
Mobility - This part is in regards to all game modes. I think a simple solution to the mobility and “walking simulation” issue is to have ATVs or Pickup Trucks that respawn on the map at primary locations like main flags and team spawns. Another thing you could add to spice up the mobility is give each team 2 options for a base spawn. For example on Kaleidoscope conquest, one team could have spawns at the north west and south west corners and the other team could have spawns at the northeast and southeast.
Cover and Line of Sight - The hard truth about this is that some of the maps just have way too many open areas that are not fun to be in. For example, Breakaway is my least favorite map BY FAR. It feels like half of the map is just wide open snow/ice and I hate playing on it. On the contrary, Manifest is my favorite map because it feels like the entire map is playable. There are unique areas and lots of cover, the vehicles have a purpose but can’t get into every single part of the map, etc. While there are a couple spots that are wide open, the map as a whole feels good when it comes to cover.
Chaos in Breakthrough - IMO the level of chaos in breakthrough with 128 players is the reason I enjoy the game mode. Sure, keep the 64 player version for those who want it but don’t get rid of the 128 player version because some people like me enjoy the chaos.
Parts of maps that lack cover:
Breakaway - Half of the map basically. Other than the areas right near the flags (Conquest) the entire right half of the map has basically no cover and is boring to play on.
Orbital - The runway leading from the tower to the rocket lacks cover, and the grassy areas on either side of the runway are also way too open especially when defending on breakthrough.
Renewal - The open grassy fields could use a bit more cover on the grass side, and the upper and bottom right sections of the B sector in conquest.
Manifest - Honestly not bad at all in most areas. Maybe more cover along the water in the bottom of sector A in breakthrough.
Discarded - Has a lot of good scattered cover but needs more in the bottom third of the map. Specifically around the D ship, and the right half of B sector (Conquest)
Hourglass - Any area that is mainly sand needs more cover. Also the little one story buildings in B sector (Breakthrough) area needs more buildings or cover or something. But yeah mainly the sand areas suck.
Kaleidoscope - Basically any area that has grass and trees needs more cover.
Lastly please fix the following bugs:
Sundance AV grenade not hitting the vehicle you aim at
Dead bodies being frozen in time standing upright
Not being able to start a match when cross-play is off
Get rid of c5 drone
Don’t put me in a game with less than 5 minutes left of playtime.
Lastly, why can my bullets pass through living enemies, but they get blocked by living team mates and dead bodies?
