I can't remember why this wasn't already present in the 1.xx series, but maintain the date of when a comic has been downloaded. I can already think of a problem with this (and maybe this is the original 1.xx issue) as downloading a comic on a particular day doesn't necessarily mean that the comic was published on that actual day.

Maybe this could be obtained via metadata/scraping additional information from the comic's page/URL and using that. The metadata method can also be used for obtaining other information for other reasons, such as a more in-depth alt-text.