Although I can understand the reasoning about pinching off the first few flowers, I don't have any real knowledge as to if it is really beneficial in the long run. But I have found a few publications that may contain those (any many more) answers for you. Sorry about all the reading.
Bell pepper production in California
Production of Sweet Bell Peppers
Bell Peppers, University of Kentucky
Greenhouse-Grown Bell Pepper Production
Bell Pepper Production
Commercial Pepper Production Handbook
P.S. Commercial greenhouse producers usually use a variety that continues to grow like tomato plants, rather than a bush type that get to a certain size and stops growing. So I am not sure if the two types are comparable when it comes to plucking the first few flowers.