I've been trying to figure out a fast way to find out which entities had a specific component changed, for example if you have a 'Health' component and you update the value of 5 of them out of 10000 I'm looking for a good way to pick that up and process it. I know about Chunk.ChangeVersion for example, but this means I'd have to iterate every entity in that chunk doesn't it? Reactive systems only support added/removed as far as I can tell, which is not what I want (I think?) - as I'm modifying an already existing component not adding or removing one. Adding a separate flag component called 'HealthChanged' or something isn't a viable solution either since it means i'd have to create a flag component just to signify that the health value changed, the same with creating a separate entity which tells you the health value of another entity changed. I've not been able to find a way to do this.