Heres my car clipping the 2-bar map couple years ago on the dyno.
Attachment 117743
Notice base timing table advance is like 17* but the commanded total is only 12*
And cyl airmass is way over the limit, no control from there. Set the 1.2g/cyl line exactly where it should be for 1.2g/cyl then use alternative provided (many different tables) means to reduce the timing further as needed.
It isn't as elegant as using a stand-alone computer but its sure a hell of a lot easier and more reproducible/predictable than scaling the entire tune if you've never scaled a tune before. Either method is a band-aid, so choose ur poison I guess