Wow looks like a healthy ass seedling honestly! Those roots are nuts too already.
edit: I can see that growing 3 seedlings in there that had root systems like that could end up in a tangled mess… I know you can “untangle” them but I feel like there’s room for some error or damage there!
Seems like it would be cool to have a plastic wall in there separating the seedlings a bit maybe. Would inhibit the space the roots have to grow a bit but… hmm