Pre 2017, ex-CAI to Asia you could take a 30 day maximum stopover on both outbound and inbound in flex J.
Now it's 7 day maximum on inbound and no stopover permitted on outbound. I think that's even the case with flex plus J too.
Whenever fares become competitive due to fx rate, EK always end up restricting the fare rules significantly. Same happened a couple of years ago our of Moscow when the rouble collapsed with the oil prices.