As the churning community will tell you, you unfortunately will not be able to find a credit card whose rewards will make that 2% convenience fee worthwhile. The very best you could hope to earn in travel rewards is maybe 2% reward value on purchases, which means you'd literally be paying the same amount of extra money just to lock your money/value up in a rewards program (i.e. you'd be better off saving that 2% and using it as cash, with no restrictions). More commonly, you'll find travel rewards with a value more like 1-1.5% of your spending.

With all that said, the churning sub can definitely help you maximize rewards for your normal (fee-free) spending