I feel that the idea is good. But...
It's true that there is not that much IPv4 "unallocated" remaining
space yet, and therefore that it mostly concerns IPv6 space.
However, if that policy is accepted and implemented, I'd say that it
should be globally done with cooperation among other RIRs and even with
space not delegated yet to any RIRs.
Just to let you know that similar policy has already been approved by APNIC community in the September meeting and awaiting APNIC EC (Board) approval this month and will be implemented max by January 2020.
So, maybe it's quite early to go on it ?
One RIR is already doing it, so I guess its not quite early for RIPE :)
Aftab A. Siddiqui
Cheers,
--
Clément Cavadore