For me , it will better disable signature from meta(imo). So it will reduce spam post. But I don't think it will happen. Regarding handover merit, it's depends on merit source and high rank member's.  They should concentrent others board as you said. There is quality post but need spend time to find. Obviously few members are trying to change posting behaviour. We should also need to welcome new member's. After implement new merit system I am trying to spend merit few new quality poster instead of send merit to high ranks.