This isn't enough because it's not a dedicated emulator that can do nothing else. I would guess you need the inability for the hardware platform to do nothing else except be an emulator for schools to even begin to trust it.
I still find using a touch screen much more frustrating than a calculator with physical buttons, but this is a legit alternative.
[1] https://acornaircraft.com/graphncalc83.html
[2] https://support.apple.com/guide/classroom/manage-app-usage-a...