Update system-firmware.md

Incorporating feedback

content/system-firmware.md

@@ -21,7 +21,7 @@ These instructions are for System76 owners who have been prompted for a firmware
 ### Before You Begin
 
 * Make sure the laptop is **plugged into the AC Adapter** for the entire firmware updating process. USB Type-C charging is **not** supported during firmware updates on the following models: Galago Pro (galp3-c, galp4), Darter Pro (darp5, darp6)
-* **Disconnect external devices**, including any displays or USB devices. The firmware update will restart and the update will not be written if external devices are connected (no error is shown).
+* **Disconnect external devices**, including any displays or USB devices. If external devices are connected, the firmware update may restart without being written (and without showing an error).
 * **Take a picture of these instructions** or pull up [s76.co/sfu](https://s76.co/sfu) on a phone or other device for reference.
 * During the firmware updating process, **the system will restart several times**. Prompts will occasionally ask for user involvement.