Caveat - this suggestion is not based on PT printing experience, but rather Kallitype (and VDB), so take it for what it's worth.
I read a while back from a 1903 article in The Photo-Minature (no, I didn't read it in 1903, I'm not that ancient) this statement wrt Kallitype printing of "thin" negatives:
"A longer or a shorter exposure, a print in sunlight in thirty seconds, or an exposure of two hours in the shade, will render possible totally different effects from the same negative." "Every amateur has among his treasures at least one negative that is dense enough in the high-lights and thin enough in the shadows to cause him lots of trouble in printing; some have several. Perhaps it will not be advisable to take the most aggravated case for the first trial, but one of the sort with which the gum worker demonstrates the superiority of his process, or one which shows bronzing in the shadows when printed with platinum paper. This sort of negative should be printed in the shade, and the more aggravated the case the longer the printing should be. As a rule, slow printing, which means an exposure of one-half hour or longer, with little or no restrainer in the developer, will give a satisfactory print from a very contrasty negative."