FAILED TO CONNECT TO QPST SERVER INSTALL
People share info about new features in the release, which A) spoils all surprises B) motivates new people to try to install it, because they feel left behind. I don't think anything good can come from installing these releases even if nothing goes wrong. No "Don't install it unless you really need it." or "Don't install it unless you know what you're doing", just "Don't.".
PSA: There is no reason to install them, so don't do it, guys. I indeed hope that your case is going to be a warning for everyone who might think about installing pre-pre-pre-release version the shady way. Let's hope you'll find a way to revive it. I am very sorry to hear your device is bricked. And the Jolla C is (hopefully) on its way, so I'd rather use my device as a 'cavy' to help posterity which may stumble upon such issue (and since you too had it it may not be that uncommon, unluckily) - and if it works I'll have a secondary phone to continue my programming tests and community will have a fix :) Weeeeell I opened a ticket on zendesk, but since my phone is from 2014 I doubt it's covered by any warranty.