[rules-users] Fusion : must declare @role(event) for all class hierarchy ?

Hi all We are using Fusion to make some simplification and grouping on some events. We have several classes of events, all derivated from a top-level class . With fusion version 5.3 (and 5.2 too), we must declare the @role(event) for the top-level class, but also for all its classes hierarchy , ie the role is not inherited by subclasses. Is it done and purpose ? Is it a bug ? Thanks.