I'm arriving late to the party, and @ErikOnSax you made great points.
The Sylphyo has very much outlived its initial purpose, that of a simple beginner's instrument, whose design, in retrospect, bears witness of our lack of understanding of the market and our own capabilities and sensibilities. Put simply, that was our first product :).
There is nothing we would like more than releasing a proper "Pro" version of the Sylphyo, or at least a huge firmware update, and there are many pieces of R&D already in place, but material reality being what it is, this is a project we cannot afford to tackle right now.
After the Loom and Omega are shipped, sure, but right now, the best we can hope for is to squeeze a few firmware updates here and there. But these updates don't have to be inconsequential, so we're glad we can hear about all the trouble people have with their Sylphyo and what more they want from it.
Concerning the keys, you certainly aren't alone in needing more keys to be able to play faster. While we wait for a new Sylphyo, there are some things that can be done.
Two years ago, a few people started to experiment with copper adhesive tape to extend the sensing area of some keys to be a bit more comfortable, and they quickly realized that if the firmware allowed it, they could be able to repurpose octave keys they didn't use on the back to materialize new playing keys on the front. A few mails later, I was informed of the idea and started working on a beta, trying things with my own dev Sylphyo:
IMG_1102.jpg IMG_1098.jpg
The last v1.5.0 includes a Copper Mod beta option to try this if you're using 3 or 3(+2) octaves and you're on the Sax/Sax alt/EWI fingerings: the + key will work as a Bb bis key, and the - key as a low C key, you just need to "reroute" them using copper tape.
Yeah, it's a big ugly hack, it looks atrocious (it could certainly be done much better, I don't care, nobody sees my Sylphyo), but it works and it could be useful to you.
Another thing that people do is simply to try and learn Sylphyo-specific fingerings. For instance, in the Sax fingering family there are a few alternatives for Bb (XxoxOoooO) or high D (XooxOoooO), Eb (XoooOooxO) and E (XooxOooxO) that could help. Others transition to the EWI fingering and develop their own shortcuts.
Again, we understand these are stopgap solutions, but they exist today, and if you think of other things we could add today, I'd love to know. The more detail the better.
About the Duduk sound, it wasn't meant to be released because it has a few bugs (squeaks) and it still has them, but we could put it back as it is in an upcoming release.