If I understand correctly the project, which I didn’t knew, I think the main difference with obtainium is that this one is portable and work on multiple platforms, not only Android. Linux, Windows and MacOS are listed.

Personally, I found Kavita and Grimmory far too complex for my use and also very resources hungry. At the end CWA is just perfect for me. Still have to configure my kobo e-reader to use it directly and this will for sure be a game changer from my current solution which consist in converting epub to kepub with kepubify and then put it on a local webserver that I open through kobo web browser.

Update: Kobo sync configured and it’s just awesome, just adding book to a shelf and sync the reader as usual and hop, everything downloads and progress updated in cwa.