In a dilemma between United Explorer and BofA Travel Rewards. Help me decide.

Some context: I'm currently at 5/24, and will drop to 4/24 on Jun 29, 2026 and to 3/24 on Oct 13, 2026. I'm looking to get into the travel cards game, and am churning the Citi Platinum Select for 80k American Airlines miles right now. Realistically, I spend between $1000-$1500 on non-rent expenses a month. My home airport is DFW, and preferred airlines is American, but I do travel with Southwest and United a fair bit.

Right now, there are the following two elevated offers I'm looking at: Chase offers the United Explorer with a SUB of 75k miles (I don't have an authorized user to add) until May 20, and BofA Travel Rewards is $250 cash back on Rakuten (only for today) + 25k miles SUB.

My initial plan was to try and apply for the United Explorer sometime in May (even though I'd still be 5/24). If, by any luck, I'm approved, I'd also apply for the CFU same day to get an additional 25k miles. But if I'm denied, I'd have to suck up to getting only 60k miles when I hit 4/24.

Now, with the BofA offer, I'm thinking to try and get 25k in BofA points, plus $250 in Rakuten cashback, which hopefully will be 25k BILT points. But if I go this route, I'd be effectively saying goodbye to the United cards for a long time. The next cards I would target would be the Citi Strata Premier and American MileUp, to double down on American Airline miles. I'd not hit 5/24 until 2028, if ever.

My questions are these: Which route do you think I should take given the context above? Also, how sensitive is Citi to the number of open lines of credit? I've already been denied for the C1 Venture in the past because I had quite a few credit cards already.