MiniSAS reverse fan-out cables with sideband

[omniscence]

There are certain mainboards (like the new X10SL7-F) that have 4x SATA connectors and a SGPIO sideband header (SFF-8448). If I wanted to connect that to a MiniSAS backplane and still use the sideband signals to control the fail LEDs, I would need a reverse breakout cable with a sideband connector. Is that correct? Do these cables even exist?