I had noticed in one of the live streams, a few months ago, that Holding the 'Alt' key while editing multiple items is a secret trick I had previously been unaware of. It really opens up the possibilities to speed up many things.
Here is a quick step by step to illustrate:
1) Grab multiple empties, (or linked collections, etc.)
2) Go to the 'Empties' tab in the properties panel. It shows the dialog to change what size the empties is shown in the viewport.
3) Enter a new value with multiples selected; and before hitting 'enter'; make sure that 'Alt' is pressed as you either hit return or click outside the entry field.
Result: You can see ALL the selected items are updated with the new value.
Though now I am frustrated to discover this trick does not work for perhaps the thing I wished it did most of all.
I have been working on a large archviz project. Managing linked data can easily become tedious and spiral out of control. Typical scenes easily surpass over 1000 individual objects. Being able to change what collection instance is assigned to a set of selected empties would save me many hours of time over a single project; if it worked as I hoped it would. But it does not.
Which is why I am here; to ask if anyone knows of a script or add-on which might accomplish the same thing. Also, would this be a 'bug', or a 'feature request'?
Seeing as how using the 'Alt' key, to apply changes to multiple objects at once, typically works on many input dialogs; it feels like it should work here as well.