aspergerguy, the workaround (Opera with proxy) lets me get to the "BUY" phase but the payment is then not possible saying there is no available payment methods for this combination of currency, location and whatnot...

I have managed to get my XperiaX bootloader unlocked now. First I tried to get it done using Windows 10 but getting the fastboot USB-drivers to install manually didn't work. (The method described in Jolla site.) I ended up dual booting to Elementary Linux where the unlocking phase worked without a hitch!

EDIT: I got the Win10 drivers to load. Had to do the windows reboot/startup troubleshooting trick and disable driver signing. In addition I had to copy additional INF file from "downloadinf_v1.01" and copy it into same directory where the Sony fastboot drivers were unzipped.