It seems to be an awful lot of admin.... I wonder how many CFAVs are claiming HTD across the RAFAC?
Why not do a specific term, say one year, with the full paperwork chain. Then, whatever you did on the year becomes your permanent annual entitlement - unless you move address, or perhaps become long-term sick. There might be +/- over a year, but the general average number of journeys would be about the same longer term.