It seems that goals are rigidly defined in terms of percentage completion, even if you choose a number instead of percentage. This doesn’t allow much flexibility in how goals are defined.
For example, I have a goal of hitting go-live on an implementation project on time or earlier, measured as the number of weeks before/after the target date. For example, -1 means I’m one week ahead of schedule and +3 means I’m 3 weeks behind. But if I set my goal as a number, I cannot enter 0 as a goal. If I enter -1 as a goal and update my status to be -1, the goal is reported purely as a percentage complete. Even if I reframed my goal to be “Days ahead of schedule” and set an ambitious goal of 14, marking myself as 7 days ahead of schedule would report that we’re half way to our goal, which doesn’t really make much sense.