Why go through emulator when u have better alts. You can try mangayomi which is still new but has a lot of options and very light.

will have to test that one. What are the supported sites? One more thing is how user friendly it is.

Tachiyomi is not officially uploaded on fdroid. So i don’t recommend using it. Download the version from github even tho they are the same.

Now for j2k, it doesn’t take a lot of time. I don’t think so. Just backup and restore in j2k and select the same download folder. That should do it.