In 3 of my seed cataloges, Johnny's, Stokes and Vesey's they say to transplant as soon as the seed leaves are 3/8 in long. I tried some peppers and tomatoes in Jiffy 7's about 2 in deep. Some varities will have a tap root into the netting before the first true leaves are even formed, Removing netting or transplanting from 2 in pots increases the chance of breaking the tap root. Once that's done the plant might as well go to the compost pile. A sweet orange cherry or Amish paste will have a 2 in tap root before the seed leaves are standing upright. Some varieties have a very fast root development, a simple test is to plant into a 1qt clear plastic food service container, and watch for roots, I have had a few plants that had surface roots 80% down the side of the container before the plant was into the 3rd true leaf stage. Byron