This is in the category of 'let's give people less excuse to not switch to Peruse'. This adds parsing of CoMet and ComicInfo.xml when there's no ACBF file available. Certain data, such as tags, usercomments are put into KFileMeta instead.
CoMet is an open 'standard' : https://www.denvog.com/comet/comet-specification/
The ComicInfo.xml is the readily reverse engineered format of http://comicrack.cyolito.com/ , and has since been used by other applications, such as ComicTagger, but also calibre plugins, etc. This one is a little bit more 'controversial' because these programs have primarily been used to order a library of proprietary comics.
I also had wanted to get in support for ComicBookInfo (https://docs.google.com/document/pub?id=1Tu9eoPWc_8SPgxx5J4-6mEaaRWLLv-bEA8i_jcIe3IE), but I cannot figure out how to get the zip comment via KArchive (though Ark is able to show the relevant zip comment just file when peeking at a cbz with embedded comicbookinfo json).
I am not really interested in making writers, because it should more be a helper when moving to Peruse, and ACBF is more detailed than either.