You can probably implement the UMP rules as a house rule, outside of the Matrix game structure, and just subtract the VP bid manually, although this would be a good game feature to incorporate into the game.
The drop out rate for players you have clearly been crushed is almost understandable. My feelings on this, is that these players are looking at months to years of playing before they recover, and this is simply too long a period of misery. A faster PBEM game would mean faster recovery in real time, and less players giving up.
One thing I see with the games I am in, is the high drop out rate from Prussia and turkey. Let's admit it, they are, for most, the two worst nations to play (personally, if France comes through with some cash, Turkey can be quite fun). In a face to face group, players stay around out of loyality, or just to hang out a day with the group if nothing else. PBEM, it seems once things go south, many times those players are done and gone. Not much that can be done about it, but never the less a problem
The Uncontrolled Major Powers Rules in the original game would fit the bill.
Although I don't think Marshall can get it in before v5.32