One of the big downsides (and the reason it became well known) is it's lack of portability, as it requires in-depth knowledge of the system's memory structures.
LWN article and previous HN discussion: https://news.ycombinator.com/item?id=11001796 Somewhat lower-level article that shines some light: http://emacshorrors.com/posts/unexecute.html
To me it seems like a fantastic way to improve startup time regardless of language or ecosystem.
On my Arch Linux installation, the node.js package takes about 18.45 MiB on disk. While I'd be glad if the various multiple electron runtimes slimmed down by 10-15 MiB, it wouldn't be much.
Why is WebGL still so heavy on the CPU?
But yeah lets stop people trying to make JavaScript faster
