In my experience kindle fire has worked the same when installing and running .apk files. I even managed to get the Google Play store working on it. I want to find the difference that is causing this issue and how to make it work
Probably, the RAM shortage is a problem. You need about 2GB free RAM just for installing apk for asset bundle installer.
Try to unpack asset bundles from .apk-files on your PC manually, and then copy them to your device.
Main apk shouldn't have such issue, I guess
Don't have one. Would a chromebook work?
Uhhh... If you have a file archiver software which supports unpacking apk, then you are good.
