Have you noticed how much "normal" additional down pressure is needed? Is it always like over 50, 80 or 100 lbs? (even when boxes are full)

If it was consistently over a certain amount, say 50 lbs, then how about extra weight on each individual row unit. (like cast iron weight, concrete block, old front tractor weights, garden tractor weights, barbell weights)

I have 5 row units, behind JD 7200 lift wheels, and seed transmission(an additional 3 ft behind frame) , for 19" rows, and I have to add concrete blocks, to 3 of them and the other get 2 frontend weights, on the two row units that follow directly behind rear tractor tires(because of more compaction); PLUS I have 3 old JD 4020 front weights on center planter frame, too, just to add weight to the main frame. {This planter went from only 8 HD down pressure sets to 15 HD down pressure spring sets = that's a lots more springs, trying to use the planter frame's weight to sink in 7 additional row units. I also removed the No-till wavy coulters, because that just increased the amount of effort needed, trying to get the row units, into the ground, into old No-till corn stalks}