Hi Matt,
Can I as why you are whitelisting MAC addresses?
As a security method, white/black listing MAC addresses is not considered by the Wi-Fi industry as either a secure or scalable solution and as you are finding is very admin-heavy.
Have you considered any alternative solutions such as 802.1X RADIUS based network access control?
Regarding your new R510, what version of firmware is it running?
Regards,
Darrel.