WiFi Dynamic VLAN and IPv6 doesn't work?

Would someone who already has a working WiFi Dynamic VLAN setup check to see if clients assigned a VLAN can hear IPv6 Router Advertisements from that VLAN?

SSIDs that have statically-assigned WiFi VLANs work just fine for me. IPv4 works just fine in a DVLAN SSID. IPv6 does not.

I've carefully read https://wiki.openwrt.org/doc/howto/wireless.security.8021x#x_dynamic_vlans_on_an_openwrt_router and both followed it to the letter, and -after that failed- made sensible deviations when that document appeared to diverge from the current state of LEDE. I'm hesitant to post my configuration, lest it attract helpful people who have never used DVLAN on LEDE/OpenWRT and are reading that document for the very first time.