What deserves a vote for quality curation is up to the individual, everyone is free to decide where to spend their votes and can change whenever they want, the same way we can for witnesses.
I'm a concept guy, not a tech guy, so I'm not sure about the difficulties, but it doesn't sound any more complicated than the witness system.
The only problems I can forsee is that it could turn into a circle jerk the same way witnesses have, but we seem to have a bunch of top 50 witnesses who want to try to change the circle jerkyness which means it should be do-able if people are interested in the idea.