There are two zip files attached to this thread:
TetheringEnabler.zip -- is magisk v6 compatible.
Tethering_Enabler-10.0.0.zip -- is magisk v10 (and later) compatible.
Please post back if you have a phone with tethering disabled and it helps you, I will then push to have it listed in the official repo. I have no tethering-locked phone so I can't test it myself.