More importantly, a quick study in logic shows there should be no
requirement for the existing space to meet RFC2050 requirements -- the space
is already allocated. After the renumbering period there's no net damage to
the IPv4 "shortage" since similar amounts of space would be assigned, but it
would be a great help to the global routing system.
The problem is that PA space is questionable. As you stated, if the only way
to do something one wants to do is to lie/cheat/steal/kill, many people
will do it.
Some of the "P" in the PA will break the rules in order to drive sales.
So, the inherent assumption that a provider is already compliant is
not a given, which strikes down the argument.
I'ld advocate for mandatory compliance checking on each allocation
request or biannually, whichever is more frequent. Of course,
I'ld also advocate that it a provider is below 25% usage, that they
have address space rescinded, including blocks not presently assigned
to any RIR. If an entity can not be contacted for 2 compliance
periods (for example, a swamp /24 to some long-dead company) that they
be considered defunct, and the space rescinded.
But, then again, I'm fairly liberal. I'm sure the more conservative
among us (and those hanging onto former customer /24s, /8s, etc)
would absolutely hate this, since they are getting something for nothing
and don't like having to play by the same rules as the rest of us.