TestStand already has an awesome tool to change multiple steps at one time, but you have to select all of those steps first by clicking on them with the mouse and using the shift and ctrl click methods. This works fine for a few steps here and there, but when you have 1000 steps you need to select that are scattered among 1500 other steps, it turns into a two day project.
I'd like to see something else that's different than the find/replace window that gives you the option to select and highlight the steps you just searched for in the sequence editor. It could be a checkbox in the find/replace tool window that gives you the option to either search for the text and display the text matches in that window, or to select the actual steps in TestStand.
I just had this problem, and ended up creating some ActiveX code to automatically blast through my sequence and change hundreds of NumericLimitTest step types to Action step types. That example code was attached to that thread.