could be a way to get extra “I” inventory confirmed beyond the limited married-segment inventory???

example:

LAX-MIA 772 I7
for ~$900

and

LAX-MIA 772 I0 Y7
MIA-SJU 76W I7
for ~$400

ticket seg1 is Y, seg 2 in I for ~$400
call the next day, say AA just released new I7 inventory for seg1, ask to be rebooked into I that’s already paid for & revalidate.
cancel within 24 hours if it doesn’t work

not quite sure how to ticket seg1 Y, seg2 I - it seems Plat AMEXTravel.com when searching business (not first) will do it, but would then have to deal with AMEX the next day rather than AA directly