The owning actor was just for example 
In actuality the UMyObject & FMyStruct can belong to anyone and therefore tick from anywhere like UObject, AActor, ACharacter, etc
Also I found FTickFunction which has bHighPriority which I can set to always make sure FMyStruct ticks first but it seems to have it’s own issues & I’m not completely sure if I’m using it properly so could you take a look at the edit I’ve made in the question?