Re: Research & book AA "Non-refundable "/"Instant Upgrade"/"YUPP" fare to maximis...
You have been as efficient as possible as AA do not have any F sectors down to the Caribbean.
The most appealing option was a couple of hops to SJU and then some more hops to LAX for a total cost of around USD1100, including an overnight hotel in Puerto Rico. IIRC, this produced around 500 SCs (slightly fewer than optimal as there were only business class seats available to and from SJU, though first class was available for all other sectors.)
You have been as efficient as possible as AA do not have any F sectors down to the Caribbean.