Yes, your long URL is editable and can be changed without changing the alias of the BudURL. You can edit the long URL by logging in, going to 'My BudURLs', and clicking the Edit icon (pencil) next to your BudURL.
Question Asked:
If I create a budURL directing to URL A, can I update the underlying URL without changing the budURL?
For example if I want to add a BUDURL in a downloadable software and change the link every week or every day without having to create an update, can I do that?