Looking like great things going on here. The Cherry Bomb genes seem to be ruling the grow so far from what I see. I've also been starting my plants in 18 oz solo cups and just promix and potting up about the same time as you have. Seems to be working well, simple and trouble free. I do give mine a little compost top dressing at about day 10, but not much, and not really sure if it's necessary, but seems to brighten them up.
I'd say good luck but it doesn't look like you need any so far.
Plants are looking nice and healthy. The #s 6 and 3 plants look like they took on a bit of early stretch. They no longer look much like Cherry bombs now, except for the leaves. Think they must be leaning more towards the OG side in structure.