I have a project that has multiple on a site and as such I need a title block per building. Sheet collections have been set up for each building. I had to update the title blocks for the sets. The architect set up the title block family to have the various and I had to go to each sheet to select the title blocks and the switch the title blocks to the correct family type per sheet collection. To be clear I opened each sheet and then started selecting title blocks while holding control to get all title blocks in a sheet collection in one fell swoop, which is still tedious.
The feature request will speed this up. When you select a family and right click, and go down to select all instances, under that flyout there are 3 options. The 4th option needs to be, select all by sheet collections, so that families with sheet collections can be selected without having to open every sheet in the collection to select and change the title block family.