First of all thank you flarmip
i would have just booked my Avios + cash flight and not used my Boston flight without knowing that it would cancel the return leg.
my flight arrives at Logan at 17:10 there is a AA flight to MIA at 18:13 not sure that’s enough time and to be honest I would rather not bother spending the night in Boston as I have a meeting in MIA the next day. You mentioned Qatar? Do they operate American flights?