Are you worried about the clocks syncing ( BT is limited range) or crowding out 2.4GHz wireless?
We check our phones, servers and bells against this once a month
Our phones are the easiest and best way for everyone to be on the same page (they keep the best time, and everyone can see them at the same time) so that is what we use as official time.
Our in class clocks are individually set, which is a pain as you know.
The website doesn't show any pricing for these clocks, what can you share with the group on pricing?