Something that I think would be completely useful, is the ability to select a previous version, and have a copy of that set to the newest version. So not exactly a rollback, as the history of deck changes would still be present.
When reviewing a past version, I find that there isn't an easy way to capture the contents to copy into note pad without significant manipulation of the result. The list version of the deck builder is the best way to do that, but you cannot get there in a historical version.
This would allow players to "revert" back to a previous version of the deck, to remove changes made while trying to enhance it. (But really just making it worse.....