In today's world for-of loops are supported everywhere, so I patched the package again and swapped out the function implementation with the original one in the source. This one single change saves about 400ms. I'm always impressed by how much CPU time we burn on wasteful polyfills or outdated downtranspilation.
So many libraries in our ecosystem suffer from this issue. I really wish there was a way to update them all with one click. Maybe we need a reverse transpiler which detects down transpilation patterns and converts it back to modern code again.