Story Arc Level Reward Merits for Dev Choice/Guest Author Arcs?

This has probably been suggested before. So what would the drawbacks be? I imagine they could use the same time metric they use for the in-game story arcs. Ie... 8 merits per median hour of game play, plus the types of arcs listed have already gone through the dev filter to reach dev choice or guest author status, so the likelihood of potential abusers would be lessened.

(Which was one of the reasons I didn't include HoF... it would be relatively easy for select groups of players to get an arc 1000 play, though to be honest if the time metric were in use, I'm not sure what form the potential abuse would take.)

The only thing that I would really see is the possibilty that heavy story arcs might be weighted a little bit too highly, since the actual in-game content could be run much faster than it would take to actually read through it all.