Hi
Well if you open the pan of cvt tranny then it would consume 4 L cvtf fluid and if you only drain it from the pan nut only then the quantity differs from 2-3.1 L and you should perform the Temperature cvtf fluid leveling. Other wise It can be either underfilled or overfilled so first choose the methord then service accordingly.
Toyota cvtf doesn't last much longer so maximum survival rate is 30k. Kms
Where as kixx cvtf fluid tends to absorb much stress and lasts upto 50k kms
Time based duration if the vehicle sits off year around then the drain time would be reduced to 2 years only.
And during normal driving conditions if vehicle is driven on daily basis then it can lasts upto 3 years.