We keep three versions of each custom form: as Task, Project and Issue so we can attach it to the request queue, the project template and a task if we convert a request as a task.
There are times we need to make extensive changes to the form and it would be very helpful to be able make the changes to one version and then save a copy using a "save over" function to update the other 2 versions.
Currently you have to update each version separately. If you delete one of the versions and then use the copy feature to replace it, wherever the form was is removed and you lose all of the data. (Hard lesson learned)