What can cause delay in SELECT statement execution and high ASYNC_NETWORK_IO even with "disregard results after execution"
Results are still returned to the client with the discard results option. The large ASYNC_NETWORK_IO wait time with discard results suggests network latency returning 221MB of data. I suggest you focus your troubleshooting on network rather than query plans.
Try a simple test by copying an 200MB file from the SQL machine to the client to see if you get similar times.