So, the rules state that you cannot connect a Y cable to another Y cable. This means that you cannot run four motors off of a single port.
If you connect a Y cable to a power expander (e.g.: Cortex motor port 2 to input A and B on the expander), would it be legal to run two Y cables from the (A & B) outputs of a power expander? The four motor load is not being put on the Cortex and you are still only putting two motors on a port.
I’m not sure of the legality of it but to me, it seems as though that is still 4 motors to one port. I have noticed that if you plug two y cables into one y cable your motors will not get an equal amount of power (compared to one motor per port), I am not sure if this will happen with the set up you have described but I would caution the possibility. I do know that my sister team did something similar to this a while back and they ended up switching it because it caused some issues with their lift.
Asked and answered. Well done @nnolte. I thought that I found an outlier.