Y-split vs separate cables

Hi- I have a marantz 8802a which offers the ability to bi-amp my front speakers via 4 xlr puts. However when you do that the processor makes you give up another channel in my case it’s he surround back speakers ( even though there are 13 connections only 11 can be used. Pretty lame). At the moment I don’t mind as I prefer the speakers being bi-amped (revel studio 2) since I have extra channels on my lexicon rx7 amplifiers and I’m changing around the room so back speakers aren’t connected.  Curious if I had audioquest make a y-split cable what that does to the voltage and other specs (on which I’m not an expert) of the signal from the processor to the amps. Fronts are crossed over around 100 hz as I have dual subs. If I used the split cable I could continue having bi-amped speakers while also being able to then run the full 7.2.4 surround.   ANy thoughts appreciated.