You shouldn't have to use the dual sim patch, the installer for lineage should see your model as dual sim and apply the properties; but if you do have trouble with your's for some reason just install the .zip as "apply update" and ignore zip signature verification prompt, and click yes to continue. You do not need to adb install it unless you don't have an sdcard.
---------- Post added at 06:33 AM ---------- Previous post was at 06:16 AM ----------
Ok, there are a few little problems about the camera if I ever wanted to mod my Sony XZ2 H8296:
- will I lose use of the dedicated camera button?
- will I be able to use the stock Sony camera app for stuff like HDR video recording, 60fps and slow-mo?
The dedicated camera button works.
Yes, recording Super-Slow-Mo, HDR, 4K, etc., video functions as it should, follow the instructions to install the original camera libraries and app.
Mod it, you are not loosing anything that makes it worth keeping stock; unless you are a purist and want everything from stock included with a custom rom, and IMO this is as close as it's going to get. Apparently, there are some image processing and focusing algorithms wiped from the phone after unlocking your bootloader that cannot be restored as of now (even with a TA backup/restore). You can always go back to stock and use the Kang kernel if you are not satisfied with the alternative OS. Make sure you follow the instructions posted on this thread and the instructions posted on lineageos.org for XZ2 - Akari.