Well, if it's "slightly" underrotated (less than or equal to 90 degrees), they'll get full credit.
When I mean slightly underrotated, I mean more than the 1/4 turn allowance. Someone shouldn't be getting a base value reduction AND an automatic -GOE consideration just because they land a jump 91 degrees less than perfectly backwards rather than 90 degrees less.
Maybe the answer would be to stop showing the judges the < and << calls.
No I don't think so. The scores need to be more reflective of what happened on the ice. If a 91 degree short jump gets a < call and was well executed otherwise, the judge should not be giving -GOE penalty. If a 90 degree short jump doesn't get a < call, then the judge should should take a small GOE deduction into consideration for the lacking rotation, thus meaning there isn't much difference in score between these two jumps that are nearly identical.