RTW1

Yes, but if you look at the chart that is clearly mentioned. Not so for the Eco+ evoucher upgrades.

I have one eco flight booked where they already have upgraded me for free to eco+. But I will probably book another return when that would be the way to get rid of my e-vouchers. But not if I need the more exoensive booking classes.

Guess only way to know for sure is to call.... But you are probably right.