I came across this tool that enables supervised mode on iOS without resetting the data. it's essentially a macOS with a unix executable file underneath. a quick guide of how it works is here
https://www.techlockdown.com/guides/enable-supervised-mode-iphone
I would appreciate any guidance on how to recreate this, as this is behind a paywall, and would like to offer something similar for free to people who want to restrict their families devices.