ePMP AP SNMP Traps?

I decided it would be worthwhile to be able to track STA registrations and be able to easily track them by MAC address, so I added a logging feature to my existing trap script (which was already logging in a txt file) to log in MySQL.

I knew that some of my ePMP APs regularly checked in to the RADIUS server, but what I didn't expect was to see one of the ePMP 2000 APs send my trap server a cambiumpmp80211SMRegTrap (OID: .1.3.6.1.4.1.17713.21.0.11) for already registered STAs which had not dropped - I assume it's related to RADIUS reauthentication, but I don't know for sure.

Is that considered normal behavior? There's no other trap which would be a suitable replacement, so I don't see how to prevent the table from getting flooded with these unnecessary entries, and I don't see a way to adjust this behavior in the configuration. Any ideas?