1.21 EntityConstructing event is no longer work

In the 1.21 the SynchedEntityData object is final and it's unable to add new Player attributes using traditional EntityConstructing. I make sense to fire the event a little earlier and pass SynchedEntityData.Builder object in it. See example below.
 

    public Entity(EntityType<?> p_19870_, Level p_19871_) {
...
        synchedentitydata$builder.define(DATA_TICKS_FROZEN, 0);
        this.defineSynchedData(synchedentitydata$builder);
        // suggested injection net.minecraftforge.event.ForgeEventFactory.onEntityConstructing(this, synchedentitydata$builder);
        this.entityData = synchedentitydata$builder.build();
        this.setPos(0.0, 0.0, 0.0);
        this.eyeHeight = this.dimensions.eyeHeight();
        // current injection
        net.minecraftforge.event.ForgeEventFactory.onEntityConstructing(this);
        this.gatherCapabilities();
    }