TIC is the configuration protocol, the tunnel can then still be proto-41, proto-41-heartbeat or AYIYA. Only the first can be setup on a AEBS (Airport Express Base Station) as software for the other two is not available for it. As for the pinging, afaik, they can't be configured properly to enable that (IMHO it is odd that they turned it off and I wonder what other ICMP's they are just dropping to the floor...) Only real way to find out is to ask Apple directly, they have an IPv6 mailinglist which is probably a good place to ask around. In the extreme case I think we might be persuaded to not do pingtests for these devices. Though, then they will not have credit increases either.