You can spend 4SH vouchers to get 2 award flights for the points of one. You still pay the taxes for both. And I suppose also the extra fees. Not sure. Does not apply to business, only economy and PE.

So when I booked the flights it was 120.000 points and about 100€ taxes to fly to Japan and back for 2 people. While the vouchers would have been worth only 40.000 as upgrades. So saved 80.000 points. Or 1500€ if you count the price of flights for one person.

Now there is the extra money costs so value is not as good, but still great IMO.