Pianotech

I've read about people who simulate down pressure of strings on the soundboard prior to getting downbearing measurements for new bridge cap on either a new soundboard or even an old one if original measurements are slightly adjusted or if many shims were added to an old board. I haven't found any more information about specific ways this down pressure can be d. Are weights added to the board? Can you use the plate struts with wedges/jacks between the soundboard and plate strut? Any description, articles, or pictures you can share would be very much appreciated. Thank you!