For the people waiting for the positive reviews flood in before they use the jailbreak:
I wouldn't have posted this thread if I wasn't absolutely sure that the jailbreak would work on every single device and firmware combination I've listed in the op.
Considering that the finalized version of the jailbreak was tested and confirmed to be working on multiple devices just yesterday, with no failed tests, this is really weird behaviour.
I'll keep you updated here whenever something changes. Here is a picture of my jailbroken Oasis 3 just to further stress that this method has been confirmed to be working on every device I've listed:
https://www.mobileread.com/forums/sh...1&postcount=48
Edit: This issue has been resolved, the jailbreak failed for devices >= 5.12.x, but now it works.