(b) If a party, in the exercise of reasonable diligence, first becomes aware after the pre-trial conference, of the necessity or desirability of using a witness, an exhibit, plot or plan, he shall forthwith provide the court and other counsel with the same information with respect to such witness, exhibit, plot or plan as is required on the pre-trial statement set forth in PA.R.C.P. 212.2. Failure to provide such information no less than 48 hours before selection of the jury, or commencement of trial in a non-jury case, shall not be compliance with this subsection, and may, in the discretion of the court, justify refusal by the court to permit the use of such witness, exhibit, hypothetical question, plot or plan at trial.