I thought the whole point of HTTP/2 was to transfer as many things as possible in one connection so maybe this bug is less of a concern for these types of connection.
The headline says "20%", which would imply that a "similar slowdown" for a 100 milliseconds response would bring it to 120 milliseconds.
But what is actually happening is that every request takes roughly an extra 0.04 milliseconds, so the time might go up to 100.04 milliseconds, probably within margin of error for most services anyway.
Seems like an easy debunk here is a test that has a more realistic response delay instead so that the slowdown can de demonstrated as an absolute amount vs. a percentage amount.
If really worried about performance, the fasthttp package is much faster than the one included in go.
"In short, fasthttp server is up to 10 times faster than net/http."
https://github.com/valyala/fasthttp