In case you are still looking for a solution to make multiple estimates inactive at once, I have a solution in QB Enterprise. I did the following:
Choose "Customers"
Choose "Income Tracker"
Choose "Unbilled Estimates" tab in the far left upper corner
Mark the estimates to be made inactive
Choose "Batch Actions" Drop Down Menu
Choose "Mark as Inactive"
I discovered that estimates that were dated prior to the closing date I had set in the company file were not eligible for batch options.
Hope this helps!
