OP-Z i/o track, compression, mixing, fx

Anyone got any technical details or done any exploration on how the i/o track works with mixer page compression? Or up for sharing compression/master chorus and drive settings they use? Or how to best integrate external synths.

A problem I have with my current setup is OP-Z drums and internal synths sound nicely mixed together but external synths through a mixer sound “laid on top” and flattens things. I’m wondering if this is because of compression or lack of on the external gear?

I was thinking of routing a couple external synths through the i/o track and that might “bed in” the external synths with the compression, drive, chorus from OP-Z and the mix sound better? I quickly tried it yesterday with one synth and it wasn’t a magic bullet, but I think I need to play more with settings.

Any advice/experiences/tips welcome! Thanks.