Nice catch all word "feuilletes"! Exactly Anneke, your great with words. I was dumb struck on explaining that.
I've never had a problem with un-even rise with puff pastry?? It could link back to you using egg wash, it could be sealing your edge down too much? Water works just as well and is more forgiving. You must try the cornsyrup addition (I forgot to mention I put a splash of h2o in the spray bottle, to slightly thin the syrup, after you apply then you continue your bake until golden brown).