[c-nsp] bgp attribute-download and VPNv4

[MKS]

Hello list

We have been using "bgp attribute-download" to get source AS number  into
netflow, and use that for traffic analysis.
However after moving the full table to a vrf, i'm not getting the AS number
info anymore (on a ASR9K)

http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r4-2/routing/command/reference/b_routing_cr42asr9k/b_routing_cr42asr9k_chapter_01.html#wp2672189923
According to cisco this command "bgp attribute-download" is only available
for IPv4 unicast address family.

Does anyone know if there is some workaround to get the source AS number
info netflow with the BGP neighbors in a vrf?
Or if this command is on the way for VPNv4?

Regards
MKS