I am purchasing a DONE3 ticket. I will have AA issue an eticket. I need to give dates for all flights before my ticket is issued. I have the following flights on the ticket at present with same day connections:- MIA - BGI - LGW - TUN. I can't stop in LGW but I can stop in BGI. I would like the flexibility to stop in BGI if my schedule allows me to (I won't know until late summer and I need to issue the rtw ticket now). How should I set this up so I do not need to pay penalities to stop in BGI later?

Thanks.