I'll jump on the bandwagon here to shamelessly plug my own little spin on Readability-based EPUB generator: It's a self-hosted OPDS server offering feeds of articles from HN, Tildes, and Pocket which are converted to EPUB on-the-fly (as soon as you try to fetch one). You can add/bookmark it in Koreader, which can run on most e-reader devices. It's simple to self-host (it's published as an image on Docker Hub and GHCR, or you can run it on Node directly).
My local instance just runs quietly on a Synology NAS; I like not having to interact with a computer to use it. Unlike the OP, it can't be used to compile many pages/URLs into a single EPUB, though.