Too little, too late.
After dealing with DEP, Apple School Manager, and just about every possible way of supervising and locking down iPads, including Cisco Meraki management, my school just gave up and binned them.
Why? ATROCIOUS AND APPALLING customer service. Literally no education department, nobody to speak to, nobody interested, asking for "the iPad serial number" when you're discussing 500 iPads all suddenly not signing into iCloud, etc. and ultimately culminating in a recorded-delivery written complaint, which resulted in a phone from "The Head of Written Complaints" who refused to confirm their name, reply in writing, or state the simplest of facts when they would not allow us to create new iTunes accounts (with a huge end-run using Apple School Manager and all kinds and ultimately never being successfully because of their "security" procedure which locks out an IP from creating accounts after a certain number a week... 5 years running of "we'll grant you a 30-day exemption only", which solved the immediate problem but was bloody stupid for a school that gets new pupils all year round, they refused to do so any more.
And if you can't be bothered to confirm ANYTHING in writing in response to a written complaint (I asked the guy if Apple could afford a printer, but he refused to answer), places like schools and businesses can't do business with you.
We WERE the talk of the local schools, with 1:1 iPad allocation. Now they form less than a quarter of our devices, among Chromebooks and Android tablets, both of which are well-supported and much easier to lock down using the Google Admin tools (which are free, but we just have to buy one Chromebook licence per Chromebook if we want to use them, which is already half the price of an iPad anyway).
Apple literally, after years and years and years of warning, couldn't be bothered to do anything more than put us on the same phone line as the grannies phoning up about forgetting their passcode. We literally NEVER received a useful answer from them and it was all guesswork and workarounds around their utter-shite. When they then destroyed the business relationship by even failing to provide details like head office address, names, handling a complaint formally, etc. then they were pulled, despite being the headmaster's favourite show-off line (and he's a mad Apple fan).
Senior team took ONE meeting with my contact log with them and the number of solutions provided (zero), plus witnessing my phone call with Mr Head of Written Complaints, and they ditched and revoked 5 years of investment within the hour.
Don't do business with Apple, they've never cared about such things. They are there to make as much money as possible from personal users and couldn't care less. Schools are ultra-ignored, the "famous" ones that are pushing Apple kit? They usually have an Apple centre on site specifically to try to convince other schools to use them (while also getting services that NOBODY else can obtain).
Google, on the other hand, has always supported, helped, and spoken to schools directly despite most of them not paying Google a penny.
Tens of thousands of pounds of hardware in the bin, not to mention about £10k worth of app licenses. Not a penny more, however. Orders of the management.
You wanna help schools? Shove it, Apple. You had more than enough chance.