Problem
When in the XML the interpolation method (interpolationMethod) is missing in the object (<Object/>), this causes a loss in the performance when generating the preview and the response has a delay.
<Object SourceID="0" Top="0mm" Left="0mm" Rotation="270" Width="239.41mm" Height="337.9mm" InsideWidth="1 rep" InsideHeight="1 rep" Id="0" />
Solution
Adding interpolationMethod="nearest" in the object will provide faster preview generation. The "nearest" value will use the nearest pixel quicker in order to generate the preview.
The interpolationMethod parameter is required when handling preview generations in Print Server.
In neoStampa jobs, the parameter is already applied.
<Object SourceID="0" Top="0mm" Left="0mm" Rotation="270" Width="239.41mm" Height="337.9mm" interpolationMethod="nearest" InsideWidth="1 rep" InsideHeight="1 rep" Id="0" />