What’s the fastest route to a second Citi Custom Cash?

I recently got the the Citi trifecta over the last few months, completing the set a few weeks ago. What Citi card offers the fastest route to PC into a second CCC?

With the upcoming PayPal nerf, I'm looking for the second CCC to replace it's 5% category, so it should be a card with the least amount of time before they'll allow a PC.

Also, I'm not sure it varies between different cards, but since I've opened 3 the cards in the last few months, I'm looking for the highest approval odds given I'm at 4/6 4/12 new cards.

A SUB would obviously be nice, but would be a secondary concern if it interferes with the PC.