For me, my favourites on the Kemper have vanished. I don't know if this happened with 2.3 or with Rig Manager.
What I do know is that ticking the favourites box in Rig Manager now is putting them as favourites in the Kemper.
hmm.. you too hey... also you can just hit store on the kemper as usual to store them in favorites... have a look in your non fav folder for your old favorites..