RE: Can You Slow Down a Servo?
I know exactly what you mean. Soon as you turn on power, ziiiiiip! and the servos center.
A couple ideas that may work or trigger another thought:
Spring selection would be tough but McMaster-Carr has quite an assortment. If you put a spring between the servo and the linkages, the initial start would extend the spring and allow the spring to retract the linkages in a more controlled manner. Maybe.
Other idea would work well but would be kinda heavy. Bimba sells little TINY pneumatic cylinders. Put one end on the linkage and the other end to something stationary, with a flow control on each end to control the servo rate at all times. It'd be kind of like a shock absorber on your car.
As far as electronically altering this..... It'd be tough. I've never heard of a device.