Al remembers well...I'm another old guy and former Bullseye & PPC shooter. We found that speeding up was pretty easy when it was based on solid fundamentals. Our fast groups were not that much worse than regular strings, no matter what range.
I see everyone now shooting at 3, 5, 7 &10 yards and enjoy having them come over to ask me what I am doing with my target at 25. Most frequent comment is "How are you doing that?" They don't seem to understand that if you do your part, group sizes only double between 25 & 50 yards, no matter how fast you do it.
Above is based on the opinion of a 20 year Small Arms Marksmanship and Training Unit USAF instructor with more than 30 years in competitive shooting sports. Your mileage may vary.