I used to operate a big sliding panel saw. The width of the groove the scoring blade cuts is dependant on the height, because the scoring blade is tapered.
We found that the best setting for melamine board and veneer ply was to score about a 64th wide of the main blade, both sides. This gave good cuts when cutting of the fence or when cutting off the sliding table. This normally meant that the scoring blade was cutting a 10th" deep in the panel +/- depending on how many times a blade was sharpened.
Hope that'll do until Tod chimes in
All the best,
**Now holding auditions for a catchy new signature**