I have use it many times. If it is a turbo application it will allow you to mount both O2's in a single pipe with no ill effects.

I had a car a few years back that when I had 2 bank fuel control turned off the fuel trims were close. I converted it to a 2 bar OS and they would be split again. I figured it had something to do with the COS.

I found on a bunch of cars it does not work like I expect it would. I found in a very few it does. I have gone over the calibrations in hex and found a few settings that may make it work, but I have not done further testing
If the sensors are in 1 pipe it fixes the fuel trims.