You can track a guy that will max at 100 in a rating. I've got
David Cue, for instance. In defense, he started at
72 (green). That turns immediately blue. At 79, it turns black. At 93, it turns orange. At 97, it turns red. His BLK rating showed
69 and 69. Max rating was 76...no doubt.
I don't think you are right about players having non-integer maximum potential ratings, but, even if you are right, then you'd still be very confident. The confusion boils down to how the integer ratings between the max and initial ratings are displayed. I got convinced that the ratings were displayed truncated, but I keep getting the sneaking suspicion that rounding is used in some places.
The slow rate of growth near the max potential rating certainly makes it more confusing. I can "know" there's 1 more point, but also know that I cannot get there.