I've tried to push a couple of UK transactions through this service. Both transactions went to 'pending' but were then subsequently cancelled several months later.

When I queried why, I was informed that the transaction was rejected as the last click through to the retailers was from another source and not KrisFlyer Spree. I complained that this must be their system and provided clear evidence that the last click through was from Spree, but never received a response. Very disappointing!