The thing to keep me in mind is...... with a stock valve body and the shift selector in “drive”, low band apply doesn’t happen.
So, from a stop, the rmvb being shifted 1-2-3 is operating the trans in the same sequence as the stock vb does.

One of my customers had the shift points set where he wanted them with the shifter in “drive”, and raced the car like that for years.
High 11’s in a 3950lb car....... no lba while racing in “D”....... never an issue.