Currently, the submitNonce requestType is accepting mining nonce submissions via POST but with the data in the query string. This is not good practice, and it should be accepting the data via the body of the POST.
To fix, I propose adding the ability for the node to accept data from either the query string or the body, with the body taking precedence if both are included. Next, update the miner software to start sending the POST request with the data in the body. Finally, after the next fork, or a few versions later, note that the node is no longer compatible with miners older than the fixed version and remove the ability to accept data from the query string.
This will bring this API request in line with best practice and understanding of API behavior.