Your description of the Bernolin sounds very interesting. I’m currently playing a plastic Aulos treble (alto). I’ve got the Zen-On which I like very much but am struggling to reach bottom F on it. I’ve also got the Mollenhauer Prima and bottom F is much easier for me to reach on that and my fingers sit more comfortably. It’s just a little shorter and that makes all the difference.
I too wish he’d make a plastic tenor – as small as possible!