@zeus I was just looking at this same issue, I think its because the GPIO's in question are tied up with SPI so dont show in Node-Red. If you find a way to get them to be visible in node-red id love to know.
I can connect to I01-I06 & I11 only on the UniPi 1.1
@zeus Thats why we do not assemble high power relays so people should use external socket relays which can be easily replaced - eg from Shack or Finder. Both have good socket relays for DIN rails.