The angle about using staff travel concessions being tax evasion is a complete red-herring in the UK. As all (ticketed) staff travel is sub-load it means that a seat is never guaranteed, therefore HMRC cannot nominate ST as a tangible 'benefit in kind' for taxation purposes.
Of course if travel is made available 'off the books' for pilots to position to their next duty on legally required days-off then who will be the wiser? You could even write into your Ops Man A that FTLs are entirely the responsibility of the pilot and nothing to do with the company....
When you operate an airline under an authority that exercises absolutely NO oversight it is quite amazing the things you can get away with!