Here's one example use case for this:

Most, if not all, of our processes include a step for "Return for Correction."

Previously, we were able to enter "return" in the search box at the top of the Monitor tab, and it would show us all instances where the current step included the word "return" - "Return for Correction," "Returned," "Returning," etc. Our support staff used this functionality regularly to keep an eye on things and reach out proactively to struggling users.

Since upgrading to v12, the search box on the Monitor tab doesn't seem to look at the Current Step column, and only returns items that have "return" (in this example) as part of the Instance name.

We've tried using a Custom Report as a workaround, but custom reports that look at all published processes just plain don't work well, and need to be updated often. And it's not practical to look at one process at a time. 

Hope this helps to explain the functionality we're missing!