I think the effect of crossed controls is negligible to take-off roll and has a very minor effect on total drag. The reason for the crossed controls is to stop one wing lifting prematurely and to stop the aircraft weathercocking into wind. So it's into wind aileron and downwind rudder. Small deflections. There is an appreciable effect on approach in a high drag, unclean and cross controlled situation. This is because the rudder creates yaw. To stop roll, aileron is used. The sustained yaw causes high form drag- drag is increased, not because of control surface deflection, but because of the larger shape of the aeroplane moving through the air. Don't be fooled by inflight control surface deflection causing unbalanced drag across the aeroplane and hence causing yaw- the drag itself is still quite low, but being caused by aileron deflection right out near the wingtips, the asymmetric effect has high moment. As proof, sudden high aileron deflection causes yaw, but no perceptible decceleration.
On a 737 simulator all-engines out drill, I ended up passing 1000' VERY high. You need to be about double the height of a powered approach- I was way above that. Full flap, gear, speedbrake- it was obvious we were still too high and going to overshoot. It was creating great mirth with the copilot and instructor. I said I had one more trick to pull out of the hat, and did full crossed controls- we came down like a lift and I completed the detail with my dignity intact! (But the underarm deodorant had failed totally)