Update your settings

Good day,
I have three Mitsubishi servos that are speed controlled from a 1515T via 0-10V analogue, with incremental encoder feedback.  Each servo is controlled by either a synchronous or positioning axis.  PLC FW 2.8, TO version 5.0.
The system works fine, but I think I can improve the tuning a bit.
I am seeking feedback about my idea for determining the Speed Control Substitute Time in the Control Loop section.  Obviously being an analogue interface, there are some delays and it would be good to compensate for these.
Here is my procedure.  Any advice or feedback would be appreciated. Thanks.
Set Kv gain to 0 and pre-control to 100%:
Set up a trace of speed setpoint, actual speed and following error.  
Trace while moving the axis to a set position.  A decent speed is required to determine the steady state following error.  But do not allow it to hit torque/current limits.
Set the Speed Control Substitute Time to the following error at target speed divided by the max speed.  E.g. if the following error is 5mm and the target speed is 500mm/sec, then set to 0.01s.
To check the results, trace the same waveform and check the following error.  The "following error is calculated from the delayed position setpoint minus the actual position in the controller".  Axis control function manual section 3.12.2