As long as there’s moisture, the seedling can come completely out of it’s shell before transplanting so don’t feel any need to rush. Most wait until the tap root is about an inch long. Don’t lay the paper towel flat. Prop the paper towel up vertical so the tap root can form perfectly straight down between the fold.

This was 4 days after planting. 18 hours on light with temps 80f. Lights off temp got down to 70f I figure just like nature. Fingers crossed for other 2. Seed stock was from 2022 so should be good to go!

No need for H2O2, and it would be bad for microorganisms