Yup, that appears to be the only thing they're used for. --- I am a dedicated member of the "Walter Sullivan Is Bad-Ass" group!!! I am the true originator of the Cookie Demon theory on the SH2 and 3 boards.
I thought it was used to open door. Later in the bench menu, I found out that it was used for an alternative payment for microtransation and the dlc is separate which could be bough in PSN store.
I bough the Tau Survival kit which contained the accelerated bot upgrade. My bot took 5 minutes to gather the resource before it return to the bench. Asking if its worth it? If you play the game slowly and due to the distance of the benches, I found the bot usually return before you found a new resource area or a bench.
The double capacity upgrade seem a bit worthy since it almost or maybe really double your resource collected. I got many ration ticket because of this and I been buying the epic resources.
The dlc just made the resource collection easy or faster but it is 100% optional if you're patient enough. --- South-east Asia PSN: Fiz57 Good! Now we can fight as warriors! Hand to hand! It is the basis of all combat! Only a fool trusts his life to a weapon! -Grey Fox