The importance of noru is to make the opponents kamae useless.
Maegeri
Applied principles of Wadoryu Karate. Enter into the space - or in
other words close the maai to your advantage. Make sure to protect
your seichusen and control (contact) the front kamae of Uke. Execute
maegeri, keep the hip and shoulders shomen. if you turn like basic
training, you will show a lot of bodymovement to your opponent. Continue
and strike Uke's face.
note: I stay there after maegeri for a short while for demonstrational
purposes and the punch is quite early in the fast versions, to be
able to make a complete punch. Still I use the whole body to punch,
not just the arm.