Use proxy manager to proxify Rules.

Rules should not be loaded with all dependent services at each start of the application.
Who knows how many services are injected by Rules ?
Instead, set each Rule as a lazy service.

BUT, the downside is that I put on and after functions as static to be able to get events without initialize the Rule object.
So it comes with less flexibility, as you cannot define complex behaviour in on and after functions.
Oh, and it breaks compatibility, obviously.

Another (better ?) idea would be to split detection and execution in 2 classes.
One Rule with on or/and after function and on Handler with one function handle which will execute what needs to be executed.
And only the Handler would be set as lazy.
BUT, the downside is that one would have to implement two classes instead of one ...