Used Eazy Plugs 3.5x3.5 cm, but missed to put some soil on the hole in the middle after I threw the seeds in.
One of them has only three leafs (2 baby leafs and only one normal)
That should be ok.
If you have a smartphone you can download a PPFD app and measure the light at the baby plant. Should be roughly 200 PPFD for new seedlings.