Boss ES-8 in guitar amp FX loop NOT 4 cabled

Hi, New member and pretty new to the world of switchers.
I have an ES-8 pedal switcher that I would like to run thru the effects loop of two amps. I know it cannot be done thru 2 amps using the 4 cable method, but does anyone know if I could run the ES-8 entirely thru the send and return of an amps effects loop - as in send from amp FX to input of ES-8 and output of ES-8 to amps FX return ? The ES-8 doesn't allow both inputs active at the same time and I wouldn't want to ( nor think it would work ) run the ES-8 thru both amps FX loops at the same time, but rather set up patches to either use input/output 1 or 2 depending on what amp I want the pedals in. I would send guitar thru an A/B/Y so I could use 1 amp dry and 1 wet, or just 1 amp period. Dirt pedals, and wah/compressor/Distillery would go into A/B/Y and I'd use the ES-8 to channel switch as well as possibly control a midi A/B switch. Is this doable? I can cable everything up but don't know what kinds of issues I might run into like ground loops, etc. I don't have the experience with this stuff to know and would like to spare my gear if doing this is a bad deal.

Actually you can do this in a 4CM but your second amp is just a slave. You run everything like you normally would 4CM with a single amp and use the second output (R) to go into the Return of your second amp. All your tone and gain staging will happen at the first amp.

Also with what you are describing with an ABY box you will need a good one with ground lift and possible phase switch.

As said,you will need good a/b box such as lehle 3sgs,or radial,ect..with ground lifts and phase reverse.