UPDATE 1st Oct: following some more experiments, we found that after applying the FlexSeal coating, there is no space to fit foam under the pack as well, the material is a synthetic rubber, is not really necessary to add both.  The case solution will work as well, it is the approach that IM US have adopted. The purpose of this secondary protection is to add a barrier to the pack, if the wheel housing sealant were to be compromised.  Raleigh, the Engineer who is managing the V10F refurbish