I can report success reaching desired 20 kmph. Upping motor current max to 150A allowed me to draw 77A max (at least that´s the reading on VX2 remote) which gave me 20 kmph.
Really appreciate everybody’s help. Feels like flying, almost 
And while standing it even brings tiny bit of adrenaline. When riding all my hopes are vested into concom´s preservative abilities to protect my remote precious. I had few dives and so far so good. Just my daughter is increasingly curious what is the function of that tiny empty tip of remote´s water protection 
