Well in Heritage racing you can run a MSD Grid in A/F, but not in JrFuel, and 7.0 Pro, I'm not sure about NE-1-2-3. NHRA Comp it's legal I have had a motor in B/ND, and that team used a Grid, it helped sometimes when the limited 12" wide tires would not get enough bite, so then they would use the grid to pull timing out and roll it back in down track. It's the same issue with the injected nitro Heritage AF cars.
Yes, another tool to use, another combination to work out.
Jon