If we were to use a pre-column, do we need to set the column length to be longer in the OPTIC software (pre-column + analytical column)?

With the OPTIC-4 it is possible to configure 2 columns in series and here it is not needed to calculate an average column length (pre + analytical column).

With OPTIC-3 this is not possible, sorry. But a 0.53 pre-column has not really an effect on the flow/pressure, so if only the analytical column is set it will work fine.