Lots of current Civil War / CZ aspects that need to go - it seems like yet another placeholder.
The first thing that needs to go is the no consequences 'pick a side' mechanic.
Open fire on a faction during a civil war, instant hostile rep. that persists, with a rep. gain for the other side that isn't instantly allied but will build fairly quickly if you're fighting with them.
The CZs themselves are a bit basic. Instead of 2 or 3 persistent large scale engagements, I'd prefer to see lots of dynamic engagements throughout the system of various sizes and types.
E.g. Large scale combat engagements, ambushes with very uneven sides, attacks on supply convoys, etc.
These dynamic engagements would only persist as long as there is active combat.
There should be faction vessels visible in SC, both logistical and combat. These can reinforce existing CZs, or potentially start new ones.
The factions should be offering a variety of special missions that will impede the oppositions combat capability, not just kill bonuses.
The Civil War itself should only last as long as the two sides can compete rather than infinite reinforcements for a week - there needs to be a ticker somewhere that tracks what resources each faction are able to put into play, and at what point they'll concede defeat.
That level of resources should be based on the populations and influence the faction has not just in the system but also potentially from other systems where the faction has a presence (inflated to provide enough combat for gameplay rather than realism).
If factions have a presence in multiple systems, then potentially the civil war should be able to spill over into those other systems to interfere with reinforcements and supplies.
Etc.