The Client Backpressure spec expands overload retry to all commands, including those not retryable under the read/write retry policies. killCursors is dispatched with no retry wrapper today (CommandCursor.killServerCursor() / AsyncCommandCursor.killServerCursorAsync()), so a SystemOverloadedError on it is surfaced immediately instead of being retried with backoff.

Scope

Add overload-only retry to cursor killCursors, gated on retryReads or retryWrites( to be clarified in the spec), mirroring the getMore implementation:

SpecRetryPolicy.IndividualPolicies(retryReads)
        .includeOverload(maxAdaptiveRetries, AS_READ_POLICY/AS_WRITE_POLICY)

Retry wraps the connection.command / commandAsync call (same connection, as required for load-balanced deployments); the failure is still swallowed by cursor close as today.