Some mobile carriers use pure IPv6 for the connecting client, including T-Mobile and others. Devices such as iPads might connect to these networks directly via built-in cellular connection (SIM card or eSIM) or by connecting to a mobile hotspot (Mifi, etc.). Regardless of the connection method, Securly Filter works as expected.
Schools should keep in mind that when these devices are connected to the Internet through the mobile provider and not through the school's Wifi network, the device will use the take-home policy because Securly sees the traffic coming from the cellular carrier and not from the registered school IP address range.
It should be noted that the carrier needs to support some technology to reach the non-ipv6 portions of the internet such as NAT64+DNS64, but it's assumed that all carriers currently do this. We have specifically tested on T-Mobile.