After resolving the mesh issues with B1200 I thought that it might be a good idea to upgrade to velica, since they are supposed to have a separate backhaul radios (correct me if I get it wrong).
Long story short, units arrived, I went through the basic installation, copied my wireguard server settings from B1200 and… I am getting like less than 1Kb per second bandwidth. Any other device using exactly the same config is able to saturate my ISP uplink (B1200, Android phone, laptop). But velica is unbelievably slow. I did re-set of the unit, no avail. Did initial setup and VPN configuration via web interface – no difference. Whatever I do, wireguard is unusable. Mullvad is the provider, but like I said, exactly the same config works just fine with any other device connected to the same network.