Purchases and pump action systems are class legal in the Wayfarer class and many of the top boats have such systems in use. But a pump action system works only when it is carefully adjusted and very well maintained. I know several good sailors that got rid of it after their pump action system failed at the least expected moment. The most reliable 2:1 system I have seen so far was a simple purchase using a singe sheave block inside the mast.
I don’t bother with spi-halyard purchases because my problem is not the hoisting speed but basically everything else. 😥
Helm and crew should master all other spi-procedures first before a hoisting purchase starts to pay off IMHO.