I would gladly, this second, without further consideration, flog them all off and buy the same number of Chromebook / Android tablets / hell, even RPi's, and spend the difference on a whole new IT Suite.
iPads are NOT built for management. They do NOT enforce settings. They do NOT have fine-grained control. They do NOT operate simply and easily (count your number of iTunes sign-ins if you push any significant number of apps to every iPad, yeah it'll "remember it" for 15 minutes but literally updates 5-10 apps every single day requiring the password in the middle of class...). They are insecure. They lock US out more than the children. They throw every obstacle possible in the way of using them. They have only a concept of a single user (so you can't share them, you can't sign in with a different account to install apps, etc. - and preloading apps can fail BECAUSE it's not the same user as you are using it as...)
And you CANNOT do it cheaply. Every time you think you can do it cheaply, you set yourself up for failure. You have to buy brand-new iPads, from an official Apple reseller, who'll only sell the latest model, every single time. Without that you can't do DEP, without DEP you can't enforce most of the settings or use Apple School Manager (don't even get me started on that pile of junk). BYOD? Ha. Yeah, right. BYOD = no DEP. You can't do BYOD with iPad (not that anyone with a brain actually WANTS to do BYOD anyway). Not even counting supervision, Find My iPad and a myriad other settings that just get in your way of doing the simplest of things (even if you're the person who supervised them!).
I have Cisco Meraki wireless, switches and device management. It does everything you can possibly do to an iPad. And you still can't lock them down.
Not forgetting that their customer service is THE WORST I've ever experienced. I've never had to tell someone that we cannot do business with a company that operates the way they do, until I started in an Apple school. Literal refusal to file a complaint, acknowledge a complaint, provides names of individuals, provide anything in writing (hell "No you can't do that" would have done me, but the Head of Written Complaints, Ireland, refuse to write a reply to my written complaint or even give me his name). They aren't data protection or GPDR-compliant and never have been, and iCloud is literally just Azure, AWS and Google server instances... TheReg published an article on it a few weeks ago.
Sorry, Apple, I could not describe a single reason to ever use you. In school. At work. Or personally.
In a recent IT audit the consultant is not the first to have uttered the phrase "Yes I hear you, but we know that all the IT guys we deal with hate Apple"... well... maybe that bloody tells you something?
YOU DO NOT WANT APPLE IN YOUR SCHOOL.
Go with Google. Free. Actually respond to support. A million times more services. And Google Classroom et al knock "iTunes U" into a cocked hat. If your school used Apple, it's because they want to show off.
(P.S. Yes. We have ceased all business with Apple, now and for the future. Compliance is a big thing nowadays and you can't do business with a company that just refuses to comply with its legal obligations).