Found the fare on ITA Matrix now. This is PNCP11FR on LX.
You are right:
TRAVEL FROM LAST STOPOVER MUST COMMENCE NO LATER THAN 3 MONTHS AFTER DEPARTURE FROM FARE ORIGIN.
And:
VALID FOR TRAVEL COMMENCING ON/BEFORE 30JUN 20.
Inother words, even with a stopover, all travel must be completed by Sept 30 (or earlier if you fly the longhaul segment before June 30).
Example:
