You can also try and coordinate your attacks with the firing, since capital ships repel culture at the planet they're located.

as advent shield migation is increased by 6% for any of your ships within your influence, if you research the appropriate culture techs. The engine creates influence and thus makes it so ships there will get that bonus.

personally I prefer the 15% damage buff vasari get within their influence.

It's a bit of a micro headache but I'm trying to blast a whole chain of planets with 1 shot each atm, it's having a noticable effect as my culture is already starting to creep in, I'm waiting for the next chain of blasts and then rushing the closest planet with my fleet. I'm hoping once one planet falls I'll start seeing a chain-reaction of planets flipping as they're all slowly losing allegiance from my planets + caps + deliverance.

Another way of looking at the guns is they're doing economic damage to opposing empires. As their allegiance drops their % income and resource mining lowers. Over time you should be able to starve them out via attrition fighting. Try wiping out as many frigate class ships as you can and take as few losses as possible, you should be able to drain them of cash/materials.

OK, the thing is, in my current game, I'm not seeing allegiance drop at all on the planets getting hit, and I'm certainly not getting the "eyes of the converted" effect. (I'm maxed out tech-wise, so I have all the culture techs)

If I saw the allegiance dropping, and it gave me a view on their planets, that'd be something useful at least. But nothing seems to be happening.

If he has a ton of capital ships in a system or lots of broadcast towers, it can essentially neutralize a single culture attack.

Yes, if you have a lot more culture tech and a bunch of stations in one place, I've seen it lowering morale at enemy planets 2 jumps away, and that place had a morale station.

Max culture decrease is only 0.05 per second so stacking multiple deliverance at the same time won't benefit you (unless he has Caps there, then you would be overcoming their resistance). That's why I've started spreading out my deliverance shots over several planets, each of them dropping at the same rate is more efficient.

Deliverance is like the more ecologically friendly version of Novalith. Since the projectiles aren't really "fast", it can take quite a while for them to finally get there, but once they do, like with the Novalith, it's an unending hail which will eventually destroy every enemy colony there with relatively little effort from you. It is, however, a very SLOW process, not at all fast. Allegiance loss is only 0.05/s, so a 100% allegiance colony would take a good 20 minutes to die from this, assuming that there is no interference from any positive culture structures or suppresors like capships. Combine that with the fact that it takes 30 minutes for the shots to likely even GET there, and several more before the shots pile up and flip culture, and you're easily looking at up to an hour or more before anything actually HAPPENS. The first signs that it's starting are when Eyes of the Converted starts actually showing you something. In the meantime, build more of them. The Advent tactical slot bonus lets you put two per planet.

It's not as immediately destructive as the TEC Novalith is, but at least it's environmentally friendly. If you set a dozen Novaliths on autofire, you can forget about colonizing anything there anytime soon, as the same 30-minute shot arrival time applies, so you're looking at maybe 30 minutes to an hour where that area is COMPLETELY UNSAFE TO COLONIZE as "Novalith Bolts" becomes your local weather, and any attempt to colonize it will result in your fledgling, or not-so-fledgling, colony being ANNIHILATED BY YOUR OWN SHOTS. In contrast, the Deliverance is "safe". You don't care if Deliverance shots strike your own planets, they do not harm you at all, and are, in fact, good for you. Rumors suggest that the Novalith was also supposed to work only in-system, and not trans-system like it presently does. Which would make it much less useful in games where everyone owns their own system.

All races get a small buff while in their own culture area, Vasari get a small damage boost, Advent get a shield buff. I'm not sure what the TEC get.

Edit:
Hrm... I remember seeing a thread about it but can't find it ATM. Maybe it was earlier in beta...

But here's a thread talking about it for Vasari / Advent
https://forums.sinsofasolarempire.com/?forumid=404&aid=300494

It takes 2 shots or so depending on how many cap ships your opponent has stationed there to get the Eyes of the converted effect. It is awesome though if you have several Deliverance Engine's, because after some time chaining them, you can see every single fleet your opponent has at a frontline planet + you can engage him with the shield mitigation bonus while he loses his own bonus (depending on race). Quite fun actually