I realise it is different for me, as I am now supporting schools in NZ, the MoE over here pays for the tennants for Google and Microsoft etc, so as far as the schools are concerened it is free. We used to use Meraki and Mosyle, but with Intune being free (to the schools) we have moved everything to intune.
It's not such an easy setup as the others, but Free is a strong word.
All the ipads (that can be) are enrolled in Apples DEP / ASM for each school and then pointed at Intune as the MDM of choice.
I have just sent out an app called seesaw to 110 ipads at one school, took me less than 5 minutes, 10 minutes later 92 have installed the app, the rest are pending.
Using an id, especially a shared one with the app store would be a big fat Nope! from me.
Plus as others have said it would contravene the terms from Apple, and as you know they are such a cuddly and fuzzy forgiving organisation.
Just to let you know, I look after 12 schools, one of which is special needs and has multiple sites, 22 all in. Without the MDM it would be a nightmare to admin, ipads alone I am looking after 1900 of them.
