Oh I see, so if I understand this correctly according to the wiki, the DoubleCash doesn't actually earn TYPs, it earns "Cashback" that you transfer into the TYP account. Downgrading Prestige -> DC would effectively be cancelling the TYP account as the sponsor account would no longer be earning TYPs, but "cashback" instead?

In theory, could I downgrade to Rewards+ without resetting the 24 month Prestige/Premier clock, and then churn another Premier (or Prestige) a couple months down the road?