1. For redeem booking, there is no difference between DM and GR. We all see the same availability online.
If no available seat, DM and GR both have to be on waiting list.

2. For waiting list, MPC elite does have priority to clear the waiting list.
Last year, I was on a waiting list TLV-HKG. In about one month, I recieved message that my waiting was cleared.
However, when checking online, nothing was available.
I assumed the system released only one seat and automatically assigned it to me.

Well, I hope MPC would offer some kinda of priority to GR on waiting list too, but Im not quite sure....