Some of my early learning was from the books by Ted Moores

http://www.bearmountainboats.com/books.htm

He was the first to address squeeging the glass and epoxy and never uses a sealer coat and the work is flawless.
I tried both ways and found it unnecessary if you adhere to the principal of heating the work space well in advance and lower the heat once the epoxy is on the boat for the first coat.
I think people could get into trouble if they use to light an epoxy coat on the first layer of glass and too much gets absorbed into the wood starving the glass. That's why Ted brushes on a liberal coat, gives it time to wet out and totally saturate the glass and later squeegees off the excess. I don't think there is any one perfect way, you just have to do what works for you. Pre sealing is good in many ways but you just have to watch out for blush and make sure your schedule allows you to glass in the time frame to allow a chemical bond.