How many Apple TVs do you have and what do you use them for?
You can decrease utilization by only using a single SSID, instead of one for student and 1 for teachers. The Radius server could check the AD group of the user and then send back and attribute based on what VLAN the user should be on.
At minimum, you can drop broadcast and multicast on the GUEST VLAN.
You can remove the lower rates on each SSID to reduce utilization
Are you using band steering to move 5ghz-capable devices to the 5ghz band?
Last but not least - ArubaOS 6.3 and above have Airgroup which would allow you to deploy bonjour, but still enable drop broadcast and multicast.