I understand the equity is the same when you run it 1-3x as pot is divided based on number of boards and equities only change 1-2% when you have say over pair vs fd, equity will be 36-38%.

My question is big pair vs big pair. I did below % based on opponent hitting set, where now there is dead card. How often do you chop when you run it 2-3x? Do you just add opponents equity together? So run it twice, chop 30%?, run it 3x chop 33% (19+11+3)? Guess its not a "chop" being 3x but 33% of the time you lose 1 out of 3?
Kk vs JJ (81\19)
KK vs JJ w\ J dead (89\11)
KK vs JJ w\ J+J dead (97\3)

Is there any merit to running it 3x with PP vs PP instead of twice?