Ah. I sat there waiting while it downloaded all 1000 channels because I didn't realize I could edit as it was working on that. I can see the benefit of having the radio verify each entry as it's being written but I don't like the idea that every modification is immediately written to the radio. I would prefer consistent behavior for each supported radio wherever possible, that of a document rather than a database approach. Just my preference of course. The desire to use channel checking by the D72 is not mutually exclusive with this approach. The changed channel would simply be queued and written when 'save' is selected.
Some other folks prefer the opposite, of course. It takes several minutes to download my ID880 (for example). It's image-based, which means the minimum time to do a download, add a channel, and upload the result is probably seven minutes. If I get distracted in the middle (which I always do), it's more like thirty minutes. With one of my live radios (like your D72) I can make a change like that in less than sixty seconds.
If you prefer the image-based approach, download the entire radio, export to CSV and make your edits there. You can then make a bunch of changes to that and only push the result to your radio when you're done.