Clearly writing custom transport is not something as easy as it seems right now since you have to configure yourself the HTTP client with all the plugins needed for authentication.

Also since the behavior of the HttpTransport by sending events immediately instead of waiting the shutdown of the application is deprecated and has a significant impact on performance.

For applications with use cases where there is a need to send events immediately regardless of performance, this is a big dilemma. Although it is possible using a compiler pass or an extension that accesses the transport properties using reflection, the solution may seem hacky and perhaps unnecessary.

Therefore the best outcome could be to give make this delay configurable so anyone can use it the way they want.