So keyboard arrived just in time. It works fine via USB and Bluetooth. Changing connection (PC cable to L5 Bluetooth) is done with no time. I just needed to web search for first connection (had to hold down a shortcut). This way I can power my phone and using the keyboard on desktop without USB-hub. Or I can plugin USB-mouse in additional.
Software failed on install. It seems there are dependency issues. I guess it happened because Byzantium runs on an outdated Debian version. I will dig into it later.