When I had a Gold Record Card, I simply travelled with only the record card when I needed its discount. Nothing said I also had to have the season ticket with me, provided I wasn't trying to actually use that ticket's validity for my journey.
The terms state...
...which seems quite clear to me
GTR also didn't require a photocard when using a smartcard, as the smartcard already had your name printed on it and they deemed that sufficient. I think this is the case for most TOCs (provided you have some kind of other ID), and the only exception to this I could find was for EMR.
Photocards with smartcard seasons seems incredibly stupid, given there is no record of a photocard number on either the smartcard or the record card. If you wanted to abuse such a season, you would just get multiple photocards with the same name and a different photo, surely?!
In any case, at least in my ticket wallet, I could put the Smartcard and Gold Record Card on top of each other in one section to avoid it being too inconvenient to carry both.