What problem does this feature solve?

I heard the diff algorithm in Vue3 is much better and faster than the one in Vue2. If do so, the performance of Vue2 should be improved largely, and the existing Vue2 apps will benefit.. Thank you very much.

What does the proposed API look like?

Replacing the diff algorithm in Vue2 with the one in Vue3

Nope, it's not a direct proportion that between pay and harvest, it's not worth doing😕

This 1) belongs into the vuejs/vue repo for Vue 2 and 2) would be little short of a rewrite of 50% of Vue 2. So don't expect that to happen in the foreseeable future.

@LinusBorg Thank you for your answers. I think improvements for Vue2, including the diff algorithm, are fairly meaningful. For there are many widely used big apps may stick to Vue2 for migrating to Vue3 is not easy. If the improvements are made, though the users of these apps may not feel, this can reduce unnecessary operations of the computing devices, which means saving energy in the world. @yyx990803 How do you think of this?