The 7% nose load figure is in common with the 85% and 100% tow ratios are just guidelines and nothing more. These offer no guarantees of a good or safe tow.
The nose weight guidance actually suggests a load of 5 to 7% of towed weight, but in fact there is no legal definitive minimum nose load, though the car manufactures do have to design the tow bar assembly will carry a minimum of 4% of the tow vehicles stated towable mass figure or 25kg whichever is bigger.
You actually only need enough nose load to keep the outfit stable. No one can tell is how much that should be.
There are those who will tell you to as high as you can, but I would add experiment by reducing the nose load gradually until you get signs of instability, then ad 5kg or 10kg, to bring it back to a safe working area.
I personally find I only need between 75 to 90% of the tow brackets capacity.