Normally I cut perpendicular to the barrel center line for best recoil absorption on hunting rifles, but on rifles used for different position
shooting, I like the adjustable but plates also.
If you cut the stock with two much negative or positive angle it is hard to get the same stock position in relation with the scope every time and you can have a shift in the POI.
I have 5 new stocks. Three of them are McMillans and two of them are Manners. The three McMillan stocks are each a different pattern but they are all cut at ~90°. The two Manners stocks are the same style. One of them is cut at ~86.5° and the other is ~85.5°. Four degrees doesn't sound like much but when compared on a hard surface it moves the muzzle a few inches. When shouldering them, they all feel comfortable.