you either need to stay analogue and use the stouffer or go digital and use the Piezography film for testing.
But you can do it any way you wish to as long as you get there. I can tell you what I do with Pt/Pd printing and if you want to use the system the way I do, you can. If you want to use the system the way you want to use it you can. Whatever gets you there is all that is important.
This is my workflow for pt/pd.
1) I standardize my chemistry. Contrast is NOT achieved by moving chemistry when making digital negatives. Rather contrast is altered with Lightroom or Photoshop.
2) I find my optimum Density Range in two steps.
a) using a sheet of unprinted Pictorico Ultra Premium OHP film I generate a step wedge of accumulative exposures to determine optimum exposure to make black on a chemistry / paper combination.
b) I print a square of 100% density onto Pictorico Ultra Premium OHP film using each of the 5 Piezography curves and expose them simultaneously with the optimum exposure to determine which curve produces "white". I use an opaque card over the edge of these black squares to make determination of "white" easier by preventing the pt/pd black to surround the white patches in the final print. That curve which produces the white I prefer is the curve that is used for all further negative making for that chemistry / paper combination.
3) I use Photoshop to adjust the contrast of the image via curve that is suitable to my desire for tonal latitude or use the Curves Calculator II or III to impart it's aesthetic. But, I prefer to use my own. We can supply you with a "starting point" photoshop curve. If you change your chemistry which changes the contrast in the final print - you need repeat this process. But I do find that the emulsion if left standardized seems to use the same optimum exposure and QTR curve. Usually 1.70 or 1.80 is the best curve for Pt/Pd. I think that Curves Calculator when used for the Photoshop curves opens the deep end too much and lowers the lights too dark. So I prefer to make my own.
hope this helps