If you have a Windows/Linux computer you could use FMD/Hakuneko to download manga. The only problem is that these tools do not scrape new releases/new chapters, and so you have to manually go in and download everything.
A workaround would be if you can find torrents for your manga. In which case, with just a little bit of regex, you could let the torrent client (qbittorrent in my case) do the searching and auto-download for you. But I don’t really rely on torrents to download manga so can’t say. I have been looking for an automated solution too.