Thing is, with your proposal you're spending 300k miles AND your 2-4-1 whereas you could get two redemption returns for 350k miles, keep your 2-4-1 and have more flexibility over the route.

In other words, you're getting bad value out of that 2-4-1 voucher.

Just looked out of interest at how many miles it costs from Tokyo to HNL - it's 80k r/t each in club with JAL (plus £300 in taxes).

Just a thought...