Here are the recipes for Kodak D-19, Kodak D-19b and Agfa 80. Sheet 1 and Sheet 2 of the attached Excel File.
You will notice that both Kodak D-19b and Agfa 80 have less Potassium Bromide and less Sodium Sulfite than Kodak D-19. Agfa 80 uses 60 grams/liter of Potassium Carbonate vs 48 grams/liter of Sodium Carbonate in Kodak D-19.
You could add some Benzotriazole solution to any of these developers. Benzotriazole is an organic restrainer and will decrease fog and also decrease Effective Film Speed.