I did the same last October ie. I booked a return trip with a 2-4-1, economy outbound and CW return- the trip is in mid August ie next month and it is only just now that seats have become available on the outbound ie. 20 days before! A pure economy redemption both ways with no voucher is a total waste I agree but if reward availability isn't there then Club one way and economy the other way and using a 2-4-1 isn't bad value once you work out the equivalent blended value per Avio for each scenario, yes it won't be as amazing as CW both ways but I was comfortable enough with what I was getting even before the CW seats turned up. Admittedly I am Gold now so don't pay any fees for changing the cabins as seats gets released which helps.