Wow, can of worms opened...
So 3 yards at 100 yards is a 0.03 difference. That would mean a 3% difference at any other given range. Using a .308 RPR shooting a 185gr Juggernaut at 2630fps (my training rifle, coincidentally) lets see what happens at 1000 yards - WITHOUT CORRECTION.
(0.03%)*(1000) = 30
1000+30=1030
The drop at 1000 yards using Strelok Pro (my primary shooting app) is 30.71 MOA
The drop at 1030 yards using Strelok Pro at 1030 is 32.25
32.25-30.71=0.54 MOA.
(0.54)*(1.047)*(10)=5.654 inches
Let's discuss an all-too-probable scenario. I show up at the range early in the morning of the day I want to shoot. I know that today's weather is forecasted at 92 degrees, but I did my work-up at 44 degrees. I stop by the sight-in board to do a quick check and I group slightly higher than usual, so I either hold bottom-of-plate on long shots, or do an actual zero adjustment. (Not wanting to change my zero stop, you can guess which one I choose). The first course-of-fire is a 12" diamond at 1020 yards. I plug in 1020 to Strelok and it tells me 31.73 MOA. Using the same math above I would have seen 30.15 MOA If I had calculated for a 103 yard zero. The bullet sails over the top of the target, most likely off-center because my wind holds aren't tuned in yet.
This actually happened. I went back to the range and found out exactly how it happened.
Now it's 7 months later and I am not in a hurry. If I would have known then what I know now, I may have had better results on that very important first course-of-fire and been much more confident on the following.
Lesson learned... Check your zero distance!