Master slave following without an encoder (6K4)

I am using a Parker Hannefin 6K4 driving 2 Mitsubishi Servos (which
act as steppers to the 6K)
 on the X and Y axis without an encoders.

I am using Master/Slave following to take laser  readings synchronized
with either the X or Y axis.
I am noticing a lag between the measurement and the XY position that
corresponds to the
acceleration and deceleration of the axis

My question is: If I added rotary encoders feedback from the motor
shafts to the 6K
would the 6K take this into consideration when sending the Trigger/
Slave pulses ?

Rephrased :
The question is really about how the 6K manages the sending of Master/
Slave pulses
?? Does it take into consideration encoders feedback when it send the
pulses ?

Thanks for any help on this