The softened numbers as you put it are just more "realistic" the actual numbers will be slightly different than these.

However this difference will be far less than the results from the ordinary very high default restraint stiffness that CAESAR II employs.

I do not understand the concern you have of double dipping. After you have the "softened" or as I would call it more realistic reaction numbers you or somebody has to evaluate these numbers and WRC107 and or FEA are the only or the most practical ways to evaluate the equipments strength.

There is no double dipping per se. However I caution you and every one else to read the WRC papers and use them within their basis.