do 4in1 esc need signal ground? i know individual esc need the ground wire. but what about 4in1?

i have a racerstar 20a v2, there is an additional red and black wire on the signal plug. as far as i can tell these do nothing.

i've been flying with those two wires disconnected with no issues for about a month now.

i just got a cicada 35a 4in1, and it has the same plug. but the red wire is missing and the black/ground is still present. 

so what is the consensus? 