6v6 is gonna be pretty close to how a 5v5 is played, without changes in the gamemode you're gonna meet a lot of dead waiting time and that's not good for the players or the spectators. Tactical options are quite limited, even if expanded a bit with 2 more players on the field. If you wanna make the games more dinamic, so that it meets your expectations and becomes more attractive to watch, you should try to cut down those wait times, and try to invest in situations where rounds are fast-paced, quick rotations and fights in every single round. This would benefit a lot those watching as it would become more entertaining, but also for the players who would find it more enjoyable.
Suggestions[Considering you wanna do 7 rounds per set]:
Time settings
-Reduce Round time from 180 to 120
-Flag Spawns at 1:30(Same speed to raise it fully --> 70 seconds)
Gold settings
-Reduce Combat Bonus Gold to 50%(+75g per kill)
-Reduce Survival Gold bonus to 50%(+250g for each who survives the round)
-Highly Recommend that you adapt all those settings as a pack, and not discard any of the time or gold settings splitting from the others as they're thought to work well together reinforcing this 6v6 with 7 rounds played per set format.
In case you accept those changes, would also be pretty convenient to adapt the map pool to such settings, try to Pick mainly maps that asure pretty easy and quick rotations(To asure Fast-Paced rotations through the round), and those who provide as many tactical options as possible without sacrificing that rotation time which will be key as you will only get 30 secs for the initial move+drops and between 70-90 to make your way to the flag or position to fight+whole fight).
·About time changes, it will add that activeness into the rounds that 5v5 and even 8v8 lacks, you will need to stay focused and move quick and constantly contest key positions to rotate or control certain flags while not rushing them(30 secs to spawn&drops + initial move and around 90 for the rotation+fight which should be enough for a 6v6 format).
·About the gold system, I didn't test the economy changes but given it a bit of thought it would provide small buffs after each round is won rewarding slightly(not enough to determine a huge advantatge on the upcoming rounds). The idea is that with most factions you can get either more armor(helmet, boots+gloves and/or shield) potentially upgrade your weapons or get new ones thing which is unorthodox with the common gold system as you rush the tanky armor straight away and later on, if any of your troops survives 3-4+ rounds potentially get a tanky upgrade which should become a decent reward for performing well several rounds in a row.
Hope the suggestions are considered at least