One of the more criticised aspects of the new, smaller format is the lack of goalkeepers, with some concerns over how that might impact their development.
The 3v3 format only lasts for 12 months, so goalkeepers do return from under-8 level when the game progresses to 5v5.
"When you make decisions like this, there are obvious trade-offs but we don't believe it is going to be detrimental to the development of future goalkeepers," Folwell added.
"Obviously playing 3v3, players can't use their hands but they are still going to be developing skills of blocking, sliding across, needing to get between the ball and the goal.
"They will also improve their ability on the ball, which we know for goalkeepers now is an increasing technique they need to have.
"We don't believe that goalkeeping is an early specialisation position. There are lots of examples of players who have come through and ended up being goalkeepers at a later age - England goalkeeper Hannah Hampton, for example, first played outfield for a long time."
Whether the new format improves the development of English footballers will not be clear for a few years yet.
But England are far from alone in opting for 3v3 at under-7 level, with the format already part of the youth structure in Germany, the Netherlands, Norway and other countries.
Indeed, it is a format that is growing in popularity across the world.
"It is the first year of adoption and obviously these things can take time to implement and for people to accept change," Folwell said.
"What we have seen is that once people have experienced it they tend to be a convert and understand why we are doing it, because the children really love it."
