Many thanks for your quick response but after reading the above
document, the product I was going to add doesn't meet the
requirements, i.e. it can't fall back to FTS-0001.
Mwah,, that's not an issue. Product codes are not limited to "mailers" in the sense of FTA-1005. Anything that creates/processes *.pkts can have an FTSC product code. If it does not do FTS-0001 just answer "no" to question 6.
Just file the request and I will see what I can do for you. There is no shortage of available product codes. ;-)