Is there a way to create custom notifications? Such as when acquiring a specific improvement or anomaly?

I say aquire here, because I want to include notification upon completetion of a specific anomaly reduction, or possibly upon capture of a system with a specific anomaly.

I tried using missions to trigger something like this, but they don't detect the anomaly until the next turn.

Hey Tychonoir!

It may be possible to do so by creating a quest:

- The quest tries to start when one of several events is received

- It has prerequisites which require the empire to own the anomaly/reduced anomaly, failing to start if it doesn't

- It is hidden and finishes immediately after showing a notification using the action Action_Message

The issue is the following events can be used to trigger a quest, but they don't include "System colonized", only "Outpost created":

EventBattleReport, EventHeroLevelup, EventTechnologyUnlocked, EventCuriosityDiscovered, EventCuriosityDiscoveredWithFleet, EventOutpostCreated, EventPlanetColonized, EventStarSystemNodeRevealed, EventSpecialNodeRevealed, EventFleetDocked, EventConstructionCompleted, EventPoliticsUnlocked, EventLawActivated, EventElectionFinished, EventPopulationBoostAvailable, EventLuxuryResourceAcquired, EventStrategicResourceAcquired

However, I still think quests are what you need, since they can do pretty much anything in the game.