B739ER, Speedbrake Lever in Flaps Up Landing

[mmrassi]

Hello Everyone,

In our FCOM there is a note for 739ER which says:
"Following an all flaps up landing, the SPEED BRAKE lever will not move beyond the FLIGHT DETENT and the spoilers will not fully deploy"

Now my question is can we move the speedbrake lever manualy and fully deploy it?
There is no notice in the QRH PI for considering the half deployment of the speedbrakes and put penalties on landing distance.

I was thinking to try this in Sim but all the Sims we use here are 800s.

Looking for your useful ideas.

Thanks