View the code and change

<CanGrow>true</CanGrow>

to <CanGrow>false</CanGrow>

This helps a little bit in the rendering time .

You could include system.io in the script task and get the fullname of the file .Then get the last number using the for each loop for file . Get the...

Instead of making multi-value for the parameter add a 3rd value to show both columns and change your expression to show the column for both the values.