If the failsafe LED only is advisory, then the only thing we need to discuss here is hints about how to fit them. It doesn€™t matter what colour they are, as long as the builder knows what they mean!

But the problem concerning the main power LED is something that we preferably would solve here and now. The way that makes the most sence to me is the following. You connect a normal changeover relay in parallel with the main power circuit, a small LED to the normally open connection, and then feed the LED from a separate battery (possibly the once powering the reciever).

This means that the robot is only safe when the LED is active (which only can happen when the removable link is out). No matter how much you argue about it, if the LED is active, the robot is safe.

Feel free to critisize any of this...