I had an electrician wire up 2x L6-30 sockets (30A 213V) and an L21-20 (20,20,20A 120V) for my space, giving me about 10kW of usable 213V and 6kW of 120V.
I PDU per outlet
I dont get the 20,20,20A 120v socket, I mean the whole three 20 thing.
Its a 5-pin outlet (L,L,L,N,G) so there are 3 phases of 120V available on the same power strip