WARBL Forum

Yes, the third octave is played by overblowing - there's no register key. That said, getting musical results from the third octave is a skill I never mastered - the WARBL might well be an improvement over my student grade band flute.

This one seems the most common, although you'd probably want to stick with the basic one.

https://www.wfg.woodwind.org/flute/

Is it possible to add fingerings for the standard Boehm concert flute? IIRC from my marching band days, the saxophone is close, but I only played the flute.