I've used rapid rooters for starting seeds, but with a twist... you know how the hole is pre-punched to be big enough for a clone?
Well, I flip the thing upside down and make a small slit with a sharp knife, and stick the seed in there for better contact with the media.
Yes, let the seeds pop first and show the tip of the taproot.
But on the other hand, I have been fine starting seeds in just plain ol coco fibre media... hekuva lot cheaper than 10 cents per plug!!!