Advice sought.

We are scheduled to arrive in MIA from Costa Rica at 17:45 on AA1600.

We depart on the 21:30 BA back to LHR. Mrs Exit & I are CW on a 241 voucher.

HBO and will be checked in for the BA flight when we arrive. With nearly four hours to connect (on non connecting tickets) what’s the likely options if we get stuck in the famously welcoming US immigration & security queues that make MAN seem well run.

Is travel insurance any good if we’ve allowed a reasonable connection time? Nearly four hours for a hbo connection doesn’t seem cutting it fine just to get through two dysfunctional queues? Views & advice welcomed.