Why does the Spring Config function not called when using Imperative API?

[dragonman225]

Hello everyone, I'd like to use the Imperative API (https://react-spring.dev/docs/concepts/imperative-api) with a Spring Config function (https://react-spring.dev/docs/advanced/config#config-per-springvalue) to customize friction, tension, etc per SpringValue, like this:

const springConfig = (key) => {
  if (key === "opacity")
    return { tension: 60, friction: 10, precision: 0.0001 };
  else if (key === "scaleX") return { tension: 58, friction: 4.3 };
  else if (key === "scaleY") return { tension: 70, friction: 4 };
  return {};
};

const animation = useSpringRef();
const springs = useSpring({
  ref: animation,
  from: { opacity: 0, scaleX: 0.96, scaleY: 0.96 },
  config: springConfig
});

but it seems that the config function is never called (example: https://codesandbox.io/s/react-spring-bug-277lrl?file=/App.js). Wondering if any of you have encountered this problem?