I just took a close look at the seed mix - there’s no hemp in there - it’s several sorts of millet, groats, flax, lettuce, mustard or rape and a couple of other small seeds I couldn’t identify. I think the two-leafed seedlings I’ve been seeing today are the mustard, but there are some grass shoots starting to poke through.
I assembled today’s webcam captures into a movie - it’s actually quite fascinating to watch the seedlings pushing their way up - they pulse as if breathing and they squirm as they come up.