Alright, under these circumstances, I guess for now it is
cai-bcn-mad-ord-mia-ccs-scl-ipc-ppt-akl-syd-sin-lhr-cai
which puts me at 33671 miles and does not leave too much space to add other destinations

.
Guess I will have to find some other cheap way to get to San Juan and/or the Cayman islands from MIA

.