There's a huge difference between solving an instance of a problem and understanding the problem. Enough commits of "this seems to fix the problem" and the codebase becomes really hard to work with.
It's not reasonable to expect that developers understand how everything works. There are billions of lines of code deployed that work for reasons that the developers either don't know or only think they know.
In this case, in my judgement, you only need to know about the delayed-ack/Nagling concepts if there's a engineering requirement to keep the flushHeaders call, and the 50ms latency is a dealbreaker (i.e. not merely a curiosity). Even then, it's not clear how to fix unless you can disable one of those features.
