[Bruno]

I recalculate the value of the Temporary Disadvantage to "Whatever percentage limitation gives you 80% the discount of the full Disadvantage" in these situations. Avoids questions of Order of Operations issues entirely.

So in this case, TD: Night Blindness is a -8% limitation (what with ATR being nicely 100 points, the math is really easy : 8/100 = 0.08 or 8%).

If you had some sort of 250 point advantage you were applying TD: Night Blindness to, it would then be a -3.2% limitation (8 points is 3.2% of 250 points).