Is SmartNet needed for access point firmware upgrades?

I’ve seen similar conversations pop up on here. For example,

http://ift.tt/2li3b6R

However, I can’t seem to find anyone with experience in exactly what I am wondering about. That post mentioned switches and ASAs, but I’m wondering about access points.

I’ve got over 175 AIR-AP2802I controlled by a 5520 WLC. Do I need SmartNet on every one of those APs in order to update their firmware?

I’d like to cover the WLC and at the most 1 AP so that I can receive firmware updates. I’ll have spares on hand to use if one should crap out. RMA that, and put it back on the shelf once it arrives.

I have seen where others have done this with access switches, but I cannot seem to find anyone with experience doing it with APs.

Any insight is appreciated.