I have done a quick search for the SR raised on Zoomtext and Supernova to GCS.
For Zoomtext I couldn't find any issue has been raised for IE11.
For Supernova, I could see that only one issue was raised and RCA for the same is given below . The customer IE version is not captured in the SR.
Super nova appears to change some of default browser settings colors, so things do not render properly.
It was observed that the prpc application/ any other application including google will not appear correctly with images and colors when the “Ignore colors specified on webpages” option is selected. (IE > Tools > Internet Options > General > Accessibility > Ignore colors specified on webpages)
Let us see if any other member of this community has faced any issues.