I dont think it would matter much either way when I start in solo's I cant fit in my dome and my seedlings do just fine. That being said, I dont think a bit of humidity would hurt either! Its a tossup, but im sure you'll do fine either way you go!
i'd leave it under a dome......take dome off gradually or open vents as new leaves appear.........or take em out when you have proper leaves,seem to grow ok either way