2.Is there any way around the 24-month restriction?
Yes. A targeted offer with a unique invitation code may offer a loophole. Numerous FTers received physical mailers in late 2015 & the first half of 2016 for which the T&C did not contain the 24-month restriction language.

The T&C for these offers will typically say instead that they are "applicable only to new accounts." This is nothing to worry about; all it means is that Citi won't retroactively match you to the offer on an account you already have; it doesn't disqualify someone who has a Citi AA card or has ever had one.

Other noteworthy aspects:

• In order to access the application page, you must have both the 9-digit invitation code and the surname of the offer recipient.
• After you authenticate the offer code and are redirected to the application page, you may enter a completely different applicant name.
• Each offer may be used multiple times--perhaps without any limit.
• Offers expire exactly two months after the nominal expiration shown on the mailer. For example, an offer with a stated May 15 expiration will be fully valid through July 14.