Thanks for the fixes!
I have one note and question.

Note:
Your changes are well structured and look good to me. I just noticed that we have redundant cloning in previously merged code part.
Unnecessary clones for serialized_request, we can remove it.

// here in non wasm target
let mut req = http::Request::new(serialized_request.clone().into_bytes());

// and here in `send_request` wasm impl
match send_request_once(serialized_request.clone(), &node.uri

LGTM!