If it weren't so detrimental to his learning, we probably would have not pushed so hard. The good news is that it was his last year of primary school when this was a problem. The next year was junior high and he had 6 different teachers.

5 of these teachers had zero issues keeping him off of the device (now an iPad). The sixth was (from what we could tell) just not particularly gifted at classroom management in general. Anyway missing out on some unknown fraction of 1/6th of his education was much less of an issue than missing out on 90% of the classroom time (thankfully there were no chromebooks in PE or Music class yet; surely they'll find a way to do that too at some point).