XPS 9730 : linux power : LED indicator not expressive

On a Linux Fedora 28 machine, the LED indicator of the power state is not very informative in sleep mode.

We have described this behaviour already in https://www.dell.com/community/Linux-General/XPS-13-9370-Standby-issues-resume-and-indicator/m-p/6095568/highlight/true#M16162. This thread about individually discussing these subjects.

When the laptop lid is closed, the LED indicator does not blink or show any sign of activity when the machine is in sleep mode. It only flashes up, when the battery goes down before dying.

It's different states are a little confusing, since one is not able to tell if a machine is powered off or in standby from the outside. Any helpful indicators provided by a firmware update would be appreciated.