It also took me a couple of goes to get through the second movement

It's true that modern repertoire pushes boundaries - after all, it's happened before in the development of recorders, with a shift from the resonant, wide-bore renaissance instruments, to the sweeter and more flexible baroque ones, which also had pushed the boundaries of range. My problem with the idea of making instruments which go ever higher is that high doesn't always sound that great - and certainly doesn't on this thing

. Most of the other boundary tweaking on recorders seems at the moment to be more about textures, special effects, microtones and suchlike, none of which need instruments to do extra notes at the top end.
As far as how loud the recorder can go, or can't, I'm not convinced we need it to. It's not an orchestral instrument, and one can't really even argue the case for making them for kids to play in school orchestras because the eagle is made of something very hard, very expensive-looking, weighs a ton, and is not suitable to hand to kids in the first place. You'd not want a thing sounding like that to do Brandenburg 2 or 4 either (thinking of situations where baroque recorders sometimes struggle to project). However, if it's a prototype, designed to be subjected to onward improvement, who knows? Maybe one day there might be a place for suchlike.
I did see a recorder with a metal head once. It sounded even nastier

.