hi bill ..

my uncle is a commercial photographer and lab guy in his 90's i am guessing.
i remember years ago we had a conversation about negatives or more specifically
solarization and he used the expression "difficult to control" too and he suggested
at that point using partially spent developer instead of fresh-stuff. all these years i have remembered that
( that was 25 years ago ! ) so whenever i hear that expression i automatically think "difficult to control means too much developer action"
perfect move making it more dilute, i wonder, did you try the same thing adding some spent developer or using "used" developer to season
your mix? dk50, harvey's 777 &c had/have wicked activity and are difficult to control until they are "seasoned" too ..
kind of like taming a wild beast

thanks for the memories