Starting a seed in a large pot will send the tap toot down to the bottom where a lot of the roots will grow leaving the upper portion of the pot almost devoid of roots. I saw off the bottom inch or so when I go from seedling cup and at each re-potting so the whole root ball is a mass of fine root hairs with no roots run around the bottom or sides of the pots. Roots branch out when the ends get chopped or air pruned like they do in smart pots or fabric grow bags so you should be ok using those.