Yes, this would be a very very helpful addition to AD. The workflow that I've encountered is this:
- I have a complex design with many symbols in it. For example, many instances of a star.
- I want to introduce some variety, so I select 1/3 of the instances, and want to replace those with a different star., or a moon, or whatever.
Similarly, I might have used Copy/Paste or Duplicate on a Group, and only later realize that I want these to be instances of a symbol. If I could select those Groups and then replace them with a symbol, preserving their placement & scale, that would then allow me to edit them all together.
Without the ability to replace these, I need to manually drag a new Symbol instance out and transform it to match for *each* of the items I want to replace, which can take hours to do :(