Spoiler deflection does indeed reduce tail clearance on the big stuff. Ask the American airline who managed to tailstrike a 777 on takeoff due to agressive aileron input.
Only if the ailerons and spoilers are kept in the same position AFTER lift off AND through out the first 10-11 degrees.
The more drag,the more pull,the more pull at low level,the less tail clearance ...simples
The ailerons and rudder should be put back to neutral positions just as the wheels gets off the ground,then pitch is increased to reach v2+15 inside the FDs.