The community who would like the knob not to be "deaggregate" are the same ones that are doing the deaggregation, which I think is as it should be from a macro level (an organism whose behaviour is harmful to itself will presumably, eventually, learn) even if it's still problematic at a micro level (the individual ASes doing the deaggregation enjoy all the benefit with only a tiny fraction of the collective cost).
As to "there must be better knobs" I think it may be a little late for that; by design (or as a consequence of it) the set of IPv6 knobs is the same as the set of IPv4 knobs.
Is there anything inherently harmful with suggesting that filtering at RIR boundaries should be expected, but those that accept somewhat more lenient boundaries are nice guys??? When the nice guys run out of resources, they can filter at RIR boundaries and say they are doing so as a security upgrade :_). Right now there isn't a hardware contention (that I'm aware of) that creates a real incentive to block deagg. But I think all of us have TE talks with ourselves and customers talking about how TE deagg w/o a covering announcement may be a bad thing (and not work for 100% of the internet, etc). Now that a number of platforms are near their IPv4 limits, lots of these deaggs are being dropped by various entities (mostly outside of their native RIR). Is there anything wrong with continuing this??? This gives preference to networks that accept deaggs from their customers (but don't leak them, etc, etc) and allows more flexibility until hardware limits rear their ugly heads again. Deepak