Arne, I would say yes, I have been flying a 6s aerobatic model with 5 Savox digital servos with a Wingstabi 7 this summer with an ESC with a 5.5v 5A SBEC with no problems.
You could always put an amp sensor in the feed to the receiver and have it alarm when you hit 3 amps.
Note the instantaneous current will increase with the voltage as the servos will provide more torque and move faster.