8/17/21 (day 9): Seeing some clawing of leaves, I'm thinking the happy frog soil is a little too hot for the seedlings and they're showing some nitrogen toxicity. Continuing to water with only distilled water in the hopes that they'll outgrow it. I also noticed a bit of over watering since I had been keeping the soil moist with a spray bottle every day. Now I'm watering via pour instead of spray and only watering every 2 to 3 days as needed, letting the soil dry out a little bit in between each watering.
8/19/21 (day 11): Update: the plants have all responded very well to the new watering cycle. I will probably water them one more time before transplanting them into their final homes (7gal fabric pots).
8/21/21 (day 13): Transplanted into 7 gallon fabric pots. The soil is a mixture of 75% Coast of Maine Stonington Blend and 25% Fox Farms Happy Frog. The roots all looked great and had taken up most of the volume of their solo cups. Watered lightly after transplanting.
Update: My wife says now we have to name them. Thoughts/ideas??