Well, I can't answer those questions myself (I have no current interest in an IBP, and I have Chase cards open for a decade or more, and a Citi card open for 30 years, so I'm not in your AAoC shoes either.

In my case, I'm waiting for a UA bonus to possibly get better (50k general or 70k targeted, while it's now 40k general or 60k targeted) after the current offer expires on Aug 15. But just because the current offer expires then doesn't prove that a better offer will appear the next day, the last time (in July) an offer expired, pretty much the same offer appeared the next day. OTOH, they historically have done bigger offers occasionally.

In my case, I already applied for Chase Marriott Business card last last year, and closed a personal and applied for a new personal Chase Marriott card earlier this year. So the only card I can possibly apply for (since I also had the existing SPG cards before) is maybe the SPG Luxury card in the 3-day window (Aug 23/24/25) before the new rules go into effect on Aug 26. But it remains to be seen whether it will really be available to anyone for 3 days. (I already have enough nights and points or years at Marriott or Marriott + SPG to get at least LTP and maybe even LTPP in the new program, so I don't need a card to get me into their lounges.)

Your question is so specific, I don't know whether anyone will be able to give you an outright recommendation.