There is at least one very simple response. Set up some deviant CIX, say
IX195-8, let everyone with a shortish 195/8 prefix connect to it either
directly through their own provider, or indirectly through some tunnel, and
have IX195-8 announce reachability of 195/8. That is, in short, altern
topology to meet addresses when the converse is too hard. KRE detailed
that for the general case, but it would be even simpler in the case of
RIPE, since all the allocated network numbers are in the same geographical
This was proposed and received mild interest about 9 months back.
I was able to persuade some people that this was a variant of
what was called "provider-based" addressing. It has the interesting
trait of also being "geographic-based" as well, for those that can
still relate to the old labels.
Not enough to take the effort to make it work. I'd be willing
to exert some, for any of the existing or planned exchanges, if
people thought this would be a viable alternative.