After a bit of googling it does look like that Asus model does support Multicast which is required for Optik TV to function properly. The one thing you'll need to be aware of is if you have any wireless Optik TV boxes they will need to be reconnected to your Asus. If all your boxes are hard wired you shouldn't have a problem as long as you enable multicast.
I found the instructions for doing so here
The instructions that were linked are for specifically setting up multicast on LAN. If the RT-86U keeps the multicast traffic only on the LAN, wifi should still work fine for your own devices but wireless Optik TV boxes won't work.
@Nighthawk Curious, are there any routers out there that work with optik tv's wireless STB? I been scouring around and I think some have got it to work with their wireless stb on their own router?
Also, I think the rt-86u has the IGMP proxy that has an incompatible message when enabling it, which is needed for optik tv to work? Not sure if there are ways around it.
Have you considered running the Asus and the T3200M together? This is what I do. My Optik boxes and the Asus are connected to the T3200M. All other devices (40 of them) are on the Asus. You will need to manage any port forwarding accordingly if you have devices you want to access remotely.