[blackflame7000]

You definitely can, I'm just arguing that the complexity involved to implement the feature is not worth the real world performance gain. Furthermore, by adding that complexity you make it that much harder to make sure the program is free of undefined behavior.

[shawnz]

Fair point, although this doesn't need to be implemented in the application code itself. In reality it should be implemented by an HTTP library like this, and any general purpose HTTP library ought to implement HTTP 2 anyway. So it could end up being that by consistently using HTTP 2 across the whole stack, you end up with less complexity. Plus you get the potential performance gains, even if small.

[KirinDave]

Just aside, performance gains in latency may not be large, but performance gains in resource utilization per connection add up quickly.