Yes, the Steigman formula was used during the crossover, IIRC. Sulfur increases contrast and speed, gold increases speed and the combination amplify both speed and contrast. This is a general rule of thumb. Gold has a tendancy to give a soft toe while increasing speed. The combination is often foggier than just sulfur alone.

Selenium and Tellurium have also been used, but are so toxic that Kodak has abandoned their use. Fuji uses Tellurium for super sensitization of emulsions.

PE