If you are playing the 5E node in SCL 7+ and hitting full progression without late joins, you should be getting a Basic Support token about every two weeks on average from Story Vault tokens (RNG doesn't make this exact).
Pulled back-to-back support tokens from the Venom Bomb vault this week! Err yey...
Both were duplicates. I tried a month or so ago to care more about supports and actually put red iso into some, but the user interface is so not user friendly and the work required to figure out who has what on an ongoing basis makes the whole system not worth the effort.