I'm >>8 and I'd like to post a small update. I've been grabbing https://en.wikipedia.org/wiki/Comic_book_archive out of the manga library and opening them using Okular and it's really straightforward and simple. I'm enjoying it so far, maybe it serves you well as well. I don't read manga titles that are still being released so I can't help with that. I assume using a combination of xmllint(1) and curl(1) on https://mangakakalot.com/ should be enough, I wonder if there are RSS feeds for this kind of things though...