Honestly, that doesn't sound like a best practice and more like a convoluted performance hack. It's one thing to use a pre-allocated memory pool for speeding up the creation of objects in native language like C++. Having to the equivalent while working several software layers above that is an example of extremely leaky abstraction.
DOM and Javascript engines still need few more man-centuries of iteration to bring their performance closer to e.g. JVM which doesn't really require hacks like that anymore.
DOM and Javascript engines still need few more man-centuries of iteration to bring their performance closer to e.g. JVM which doesn't really require hacks like that anymore.