If the animation engine is capable of smoothly changing a value in JS, I think it would already integrate very well with Svader.

The way the reactive rerendering works, is that every time a change in the input parameters is detected it queues a requestAnimationFrame, so yes, it follows the browser refresh rate.

Since Svelte 5 is automatically able to track changes in values, both by reassignment as well as object mutation, anything that changes a value -- no matter if it's designed for Svelte or not -- should be able to integrate smoothly.