Keep in mind that the Omnipressor algo sums both inputs to mono, so if you want a stereo Omnipressor you'll need two of them.
also note that there are two Omnipressor algorithms. #1116, and #6517. After skimming both of them in Vsig3, they do seem to be slightly different.
here's a copy of the Omnipressor plug-in preset "Over Easy Mastering" for #6517, which I'm a fan of https://drive.google.com/file/d/18-P5XEGglyMUCYEjIeaqqYlktlQWRvJb/view?usp=sharing I put two of them side by side and run the left channel into one, and the right channel into the other.
and I just stumbled across this and got a kick out of it https://www.eventideaudio.com/presenting-eventide-omnipressor