Any problem with a seperate ULA interface and a GUA interface in same VLAN?

[jasonistre]

Will this cause any MAC address flapping, multicast, or arp table problems? Two separate physical interfaces. 

LAN (igb1) is assigned a ULA and DHCPv6 issues static reservations to clients.  It also has the IPv4 and DHCPv4.
LAN2 (igb2) is assigned to track interface WAN and uses RA with SLAAC.

Clients get ULAs, GUAs, and generate those privacy temporary GUA addresses and everything seems to work well.  The firewall does sees the same mac addresses out both LAN,LAN2 ports for the same clients with the ULAs being on LAN and GUAs on LAN2.  Any sort of problem or potential problem with this?

I originally tried a VIP, but VIP cant track WAN for RA SLAAC, and if I put ULA on VIP then DHCPv6 has to be used for GUA and my ULA become SLAAC.