Player A has been spotting player B 9-7 and player B rarely wins.
Should the adjustment be
player B gets 9-6
player B get 10-7
player B gets 9-7 and the break
I'm thinking 10-7 is the next step.
You can work out a spot table based on the ideas of FargoRate. Below is a table of the equivalent FargoRate difference between skill levels and fair spots.
After 9-7, the next greater spot commonly played is 8-6, the equivalent of a 6-point adjustment. If you want to adjust half of that much, play 8-6 on the stronger player's break and 9-7 on the weaker player's break. That would be a change of 3 FargoRate points which is pretty much nothing.
For more details, see the November 2019 issue of Billiards Digest.
The break as a spot depends on the players. For some players it is a disadvantage to break because the corner ball comes out so often.
The green-shaded games are within one ball of 15 balls -- either one ball spots at the start or one ball is left at the end.