Roger, ammonia speeds up the fixing process. I beleive it should not be added to the sodium thiosulfate as it bleaches the image too much.
Those who add more FO and Silver are of the opinion that if a little bit is good more is better. I have seen no evidence that mor FO or silver give you a better image with greater D max. IMO it is the paper and sizing you use rather than the amount.
I just started doing Kallytipes and I am having a lot of fun with it. I use it to proof negatives for pt/pd and it is a wonderful tool. Since I have the pd I tone them with it and I have to admit some look as good if not better than the pt prints.
Hope this helped.
Opps...I missed a not.....sorry.