I'm surprised, as gold tends to soften toe in paper emulsions and lower contrast.

Well, I guess it depends on what curve shape or effect you want as to what addenda you are free to use.

Typically, gold is used in film to get long scales, and cadmium was used to get high contrast in papers. Cadmium is no longer used in most commercial papers, but some smaller photo companies still use it to make papers with sharp toe and high contrast.