First off, I'm not a dev so maybe I'm way off base with what I'll say. From my POV, Go is more and more problematic, since the http/2 support is kind of broken with bad performances, and http/3 is not being worked on by them If I believe this thread net/http: support HTTP/3 · Issue #32204 · golang/go · GitHub
If http2 is giving you problems then try --disable-http2. With the current Go implementation this will be faster for pure transfer speeds (see go issue #47840. http2 can still be better for latency though.
It would probably be possible to implement this library in rclone's HTTP transport making it seamlessly available to all rclone HTTP connections.
I already use -disable-http2 everywhere, but I find it sad in the end because we're stuck with http "one", which has "problems" , not due to bad implémentation but just old age, too.
I hope we'll have a good http2 implémentation or even better quic support one day