You can also use komf alongside komga/kavita to just scrape metadata automatically upon import. A bit finnicky to get going (a tampermonkey script is required to give it accessible setting on the komga page) but works very well and even has a gui for identifying results and selecting the correct option if the auto scrape fails similar to jellyfin

For the actual reader part I just use komga as a server and read through Mihon (one of the tachiyomi forks) on my ereader mostly. occasionally I’ll use paperback on my iphone (although recently I’ve been trying Tachimanga, which is basically an iOS tachiyomi fork). Loads library, can sort by tag/library/date added, reads most things very well, can sync read status with the komga server (and/or manga updates or whatever), etc.