If a single 6rd instance is accepted as a rule the end result of that will be that every ISP in the world with non-contiguous allocations will be asking for a /24 next, knowing full well that they're only going to use 0,1% of the network side of that space, ever.
A lot of numbers have been thrown around fairly casually in this conversation, but /24 is a nice one to focus on because everyone understands how many /24s there are in a number space. If we could have run the IPv4 Internet by only giving every ISP a single /24, then we would never have run out of IPv4 addresses. Conversely, giving every ISP an IPv6 /24 is not radical and is not even wasteful given the large number of /24s that we have in stock at RIPE and at IANA. As for your comment about 0.1%, I'd like to know how you calculated that number. In general, I'm only interested in numbers that count /56s (or /48s) and /32s since those are the only ones that are meaningful in making policy. --Michael Dillon