The lovely and helpful stevepusser over at Debian forums actually built a 0.4.0 deb, which installs and runs perfectly. Amazing!
You can find it here: https://software.opensuse.org//download ... bxcb-util1
With this, I can now run the 6857 builds.
In Carla they work ok, with resizing and so, but a noticeable lag (even though it feels like Zebra lags less than Repro).
In Qtractor, which is where I do stuff, they all appear as grey boxes.
But it seems Qtractor is a lost case anyway, so I guess I'll stick to 6640 no matter what.
Zebra 2.8 is really nice, by the way. I've only been using the old Zebra2 before, and the GUI improvements are great!

