Since you only worm your birds twice a year, I wouldnt even worry about rotating wormers.
I rotate wormers every few months, that's because I worm my birds monthly.
Since we're not sure about the Wazine's effectiveness, go ahead and give your birds the Safeguard in 2 weeks for 5 days straight and then you'll be completely done with worming.
Worming for 5 days straight will take care of all types of worms (except tapeworms) especially capillary worms if your birds have them. Then your birds will be good to go.