Where did you get that from? The drivers for NVIDIA networking cards are in the upstream kernel. You have the option of using newer versions from DKMS if the built-in version for your kernel is too old.
For Windows 10 Mobile, app sideloading with any signature has been implemented since the beginning. You can just install a .appx(bundle) directly, with no dev account system being present unlike WP8(.1).
You don't need a translator. The ABI is a software construct, not an hardware one.
What would be needed though is to have two copies of the system libraries in such a case, targeting different ABIs. That's of course very unlikely to happen.
My guess is that their camera supplier has a secret blob that they want to retain encrypted...