Here is a feature that I've seen in another editor that's really useful. I would like to add a feature to the multi-selection that makes it quick to select all the instances of a particular word. Now, a double-click on a word selects that word. I want to be able to CTRL-DoubleClick to multi-select all instances of that word.

This would be a quick way to replace all instances of the chosen word: CTRL-DoubleClick then start typing to replace them all at the same time.