Rainboe. You said:
I don't think spoiler drag is a big problem on take-off- all the speedbrakes aren't exactly powerful even at 250 kts on a 737. A couple just floating up gently below 150 kts isn't really going to have any effect dragwise at all.
The FCTM states large control wheel inputs can have an adverse effect on directional control near V1 (MCG) due to additional drag of the extended spoilers....limit control wheel input to that required to keep wings level....use of excessive control wheel may cause spoilers to rise which has the effect of reducing tail clearance.... incorrect use of control wheel input will cause spoilers to extend and increase the take off distance.
And you don't think spoiler drag is a big problem on take off?