Nós vemos em vários episódios, como " The Siege, Parte 3 "que o uso de uma capa nega qualquer blindagem que a embarcação possa possuir. Dado que eles estão entrando em uma situação desconhecida (onde o inimigo pode simplesmente estar atirando continuamente no portão), faz sentido tático usar os escudos principais ao entrar no portão, então o manto depois.
No episódio " O Santuário " vemos precisamente esta situação. Eu editei por brevidade ...
In the Gateroom, a M.A.L.P. trundles into the open Stargate. As it reaches the other side, Richard looks at the video footage which it is sending back. Two Wraith Hive ships are on the ground on hillsides either side of the Gate. He reports on what he's seeing.
WOOLSEY: The M.A.L.P. is clear of the Gate and they're firing on it from both sides of what appears to be a deep valley.
The Jumper lowers down into the Gateroom.
WOOLSEY: It's deploying smoke. You should have complete coverage of the area in five seconds.
(The Jumper flies into the Gate.)
TALUS. The Jumper exits the Gate and soars forward through a thick cloud of smoke. Its cloak can be heard deploying as it races up into the sky. It turns around and heads back the way it came to take a look at the two Hive ships.
TEYLA: Do you think they detected us before we were able to cloak?
SHEPPARD: No, I think the smokescreen worked. Hopefully they think we just sent the M.A.L.P. through ahead of us and changed our mind when they blew it up.