I would like to use the files in a previous package as the starting point of a new package. I know I can create a second package and merge them, but I would like to remove some as well.
Thanks for bringing the ticket up! We are currently on preparation and testing for the next release. We will look into these next batch of enhancements most probably after this upcoming release.
We will update the ticket once we have more or once we have started on that enhancement.
On a related matter, there is also an “Upload” button feature where you can you can specific before hand the items you would like to select during Manual package creation.