It is not really a question of the RTM, it is the matter of the Manufacturer part number pulling into the RFQ when it is created in the first place.  PO-E (at least the latest IS Tech version) does pull them in but I recall a previous post that using MRP to generate the RFQ did not.  Let me know if that is really the issue and I will take a look at MR-K.  
 
Regardless, you can't add data fields to TAS 5 RTMs, only TAS 6 Evolution and then only if the file you need to pull the data from has aready been opened by the program.