If the problems are graded the exact same, and all the little points are added up and deducted, it will result in more people actually failing in the simulators. I'd be surprised if many facilities have come up with ways to add positive points back in.
16 points for a separation loss, but possible for 5 points (or 4?) to be added back in the separation category. I can only see that happening if there's problems designed to have a separation loss, but the trainee saw the conflict and fixed it.
Only way I can see this working (and the memo should have included it) is to describe how to add positive points. TETRA uses a set number of "goals" that can be accomplished in the problem. The goals include things like: aircraft crossing the threshold, leaving the lateral confines of the airspace, getting airbone as a satellite departure, etc. Each goal is worth something like 2.5 or 3.3 points.
Nationwide, facilities are going to have to rework their problems to get an effective scoring system in place. Or, have someone work the problem in an efficient way and determine what the positive points are going to be. The negative points are easy enough to figure out, but those are going to add up quick...especially on the 100-125% problems.