iPad remote management, but not on apples DEP I have a dilemma. I work for a decentralized organization with independent business units.  We’re now starting to centralize the support of IT. 
I have a few companies who bought their own iPads from like Best Buy, amazon and the Apple Store. I had read that you cannot enter consumer purchased iPads into the DEP program.
I have 20 iPads I want to manage and maintain, but it also seems like an Apple ID is a MUST to do literally anything. I read somewhere that an Apple ID has a max limit of 10 devices.
The other problem is when I add a new iPad it sends alerts to ALL the other iPads, which could interrupt or scare a user in a different location.

My question is, how best can I manage and maintain 20+ iPads? I’m currently using InTune, but features a limited without Apples DEP and still requires an AppleID to install any apps.
Check out What's new in DEP from WWDC17. All devices can now be enrolled into DEP regardless of purchase source. Apple Configurator will allow you to provision any device for DEP however these device will be put into a 30 day trial period where the device will display a warning on the lock screen and can be un enrolled at any time.