The idea of it being the default lighting or a HUD was thrown out years ago. I only mentioned in relation to ROAST which is my preferred acronym for the new spin off 😄
Having one walker switch on a red light some way into the battle would establish this is something that happens for reasons we don’t need to know, but isn’t the default setting or signifying the leader or anything like that.
But as I said I am aware that if the ST isn’t important to this project the spin offs are probably less so.