IPv6 Subnet delegation

All,

I hope there are someone out there that can help restore my sanity after a call with level 2 support today.  It started with my request for a IPv6 PTR record to our main router which issues a DHCP-PD call from our router (Mikrotik) to Comcast's DPC3941 to get a portion of the /56 static range we have been assigned. The problem is that static is not static.

Since there is no way to define static routes in the 3941, our only option (it seems) is to issue a request to the DHCP-PD deamon.  We do that by defining a pool on the router and set the hint to 56. However, whatever we do, we only get a /59 delegation i.e. 32 subnets. Since we need more than that (PTP links/VLANs/etc) we are struggeling.

With IPv4 we were able to create a walled off network between all our nodes using a private range. Not so with IPv6 as global addressing is a must.  That means that all parties needs to operate wiht the same addressing topology and Comcast imposed restrictions hurts us with other nodes located in different countries or ISPs.

I appreciate the fact that we now have a static /56 assigned to us. However, without the ability to add IPv6 routes to the 3941 the utility of that is limited.  Do any of you know if there is a way to add a route to the 3941 so that we do get more subnets and not have to deal with the dynamic nature of the DHCP-PD deamon in the 3941?

Any pointers would be much appreciated.