@Jim D. Yeah, I'll just have to make a tweak or two next time. My inverted puff rose well, and when I placed the tray on top I could tell my cobbled-together spacers could've done with a few more millimeters; that, together with too much weight, meant I could feel the pastry pressing onto the filling. This video gives you an idea how it works (and some bakers put the tray there from the start; not sure what the difference is).