Thanks Maxence ... yes, I've got that ... but the "3" in "C3" could mean (as I've found out recently) many different things depending on the octave numbering you use. The Sylphyo (from my examining the MIDI stream it puts out) puts out MIDI hex 3C = decimal 60 for "C3" which is Middle C. That's the same standard that Kontakt, Apple Logic, Cubase, Steinberg, and Yamaha keyboards use.
However, the ISO standard that is used by Korg, Roland, and most of the piano tuning and composing world (and also the Native flute world) use "C4" for Middle C. That's why I was always off by an octave before I understood these issues.
Cakewalk Sonar actually uses C5 for Middle C, which is really confusing!
You are not doing anything wrong.
The up/down buttons are only providing this next/previous feature when NOT paired with the Sylphyo. When you are using the Sylphyo this is achieved by the Sylphyo keys instead.
I've also had my share of "what's that thing" and improvised 30-second demos for airport security officers :), but I never had any issue, be it with our without a case. As it contains a battery, you need to take it in cabin.
I also fly with some of our weirdest electronics prototypes without their enclosure and with wires everywhere, but it hasn't raised any concern so far.
@clint so far the durable SLA seems to work well, it's quite rigid and is holding up to daily practice. The 2.3mm was a bit too narrow for the sensor, it produced some held note behavior from the back-pressure with certain articulations. I think the next size up is going to be my keeper. Thank you again!