Interesting idea, but the one thing that jumps out at me is that it's simply going to be too long of a game. I don't really know how many people would be interested in playing games that can last up to 35 minutes.

Those 35 minutes would be fun if there's balanced fighting going on. But currently there are too many matches where teams get redlined, and who wants to play in such a match that can go on for a while? If you are the attacking team, redlining the enemy would simply mean an easy hack and win. But if the defending team is redlining the attacking team, then the game would either go on for 30 minutes after the initial 5 minutes or until the attacker's clones are depleted. From my experience in Skirmishes, teams are rarely cloned out within the time limit of a full match.

Also, there'd need to be a damn good reason for players to sit idle for 5 minutes while the defending commander sets up the installations. This would make this game mode more suitable outside of Instant Battles, and the time spent in the warbarge for PC and FW could instead be used for setting up the installations and when players get deployed they can start fighting immediately.

Something very similar to your idea is Skirmish 1.0. The attacking team needs to hack multiple objectives to get their MCC to dock which wins them the match. Attackers are limited on clones but the defenders are not. But your game mode still has its own unique features. It would make PC battles more realistic, because why shouldn't the defenders and owners of a district be able to set up the installations however they want?

Edit: to answer your questions, I cannot come up with a name either. Multiple bases should only be introduced if a single base is too easy for the attackers. Vehicles should be allowed, I don't see why not. And like I said above, this game mode should not be in Instant Battle, but rather in PC and FW. For FW though, I don't know how the field commander will be chosen because it could just as well be a rookie in his own squad making poor decisions.

I like the idea. skirmishes already take 20 to 30 minutes for me most of the time so this game mode would not seem to last much longer for a lot of people unless one team is constantly being redlined and as a result no one would be having fun.

How about giving the defending team the ability to deploy installations after the match has started but each individual defending player can only deploy 2 installations at max (that are already hacked) for the whole match. That way installations would be more useful. (because they could surprise the attacking team by dropping down suddenly and be taken control of by a defending player instantly, catching the enemy in the open sometimes as they attack in waves)

All the installations would be destroyed very quickly at the start of a match, thus making them useless (because its hard to kill swarm launcher players at 200m with a installation), if they were deployed before the attacking team started its attack. The attacking team would deploy at a range greater than 400m from the objective, at the start of the match like in skirmish, would they not?

16 players multiplied by 2 gives 32 installations a match.