Gen the Agg use AS-SET without the summary only key word command, *prevents R1 from learning and installing the summary locally .. on r3 also create a ipv6 prefix-list allowing only the agg out to R4. no reason to unsuppress anything.
Also I think 3.1 the IPv6 config portion added an additional frame map statement on R4 that wasn't needed to R2.
i never configured this and my solution worked fine.
As long as you have R3's link-local covered in the map you'll be fine, and of course the main interface to R2
frame-relay map ipv6 FEC0:234::2 403
sg: frame-relay map ipv6 FE80::2 403 NOT NEEDED..