Hi,
I know this is an older thread, but I recently released a beta that was created for exactly this use case: browsing and downloading from an OPDS catalog while remaining in the standard Kobo/Nickel interface, without replacing it with KOReader.
KoboOPDS supports multiple sources, HTTP Basic authentication, search, pagination and automatic import of downloaded books into the normal Kobo library. It is launched through NickelMenu.
The first tested device is a Libra Colour, so the Aura Edition 2 is not verified yet. If you still have the device and would be willing to test it with Kavita, your feedback would be extremely useful:
https://www.mobileread.com/forums/sh...38#post4605338
Thank you!