“A line has to be drawn as to what evidence can be considered as PPE and what evidence we considered the subject of a special preparation claim. Each case depends on its own facts. The regulations do not state that every piece of electronically served evidence, whether relevant or not, should be remunerated as PPE. Quite the contrary, as electronically served exhibits can only be remunerated as PPE if the Determining Officer decides that it is appropriate to do so, taking into account the nature of the documentation and all the relevant circumstances.”