So, considering the fact that CA is one of the most popular quake gametype, and also considering the fact that it has its flaws, I think I have some very simple ideas to improve it.

1°) Make the use of the different Champions available, unlike duel, I think that the Champions can improve the depth of the gameplay without breaking everything up. It can actually be a quite nice addition and bring some more interesting "strategies" or tactics to CA.

2°)a) Make something kind of like Domination, but instead of having to control multiple points in the map, make something like a "King Of The Hill" approach, where you have to control a large "zone/area" on the map, but not necessarily always "bridge" or "top". Make the large zone/area you have to control always change position at each new round. With indications of where you have to go to "control" the map before the round starts.

2°)b) Obviously the maps have to be big (unlike asylum), like Overkill or even TheaterOfPain in order for the gametype to not end up behind completely chaotics RL only battles. Allow the players to have space to move and dodge within the different zones/areas you have to control each new round.

3°)a) Add something like "regeneration" when you stay in the zone/area, like you gain 1-2 HP or 1-2 AP, or both, each second (or maybe like every 2-3 seconds or something) you stay in the zone/area. Obviously the regeneration has to be very slow and makes you gain only a few amount of health/armor over time, so that it doesn't make it completely "imbalanced" or unfair when you're not in the zone/area.

3°)b) Add something like "degeneration" when you're out of the zone/area, maybe after 2 or 3 minutes, if nobody from your team is in the zone, or you're the last man standing (and still not in the zone/area), your HP/AP start to decrease slowly over time.