After writing a new short extension about this (to be reviewed soon, Review "Power profile indicator" version 1 - GNOME Shell Extensions), I realize that’s somewhat odd that this indicator is not displayed by default (or is this a bug on my Ubunutu 24.04 dev ?).
All other quick settings indicators do appear in panel (except dark mode one, but I agree this one is useless !). Should I ask for that in GS gitlab or is this a fixed design decision ?
Is there a simple way to execute some code after quick settings indicators are ready ? After start-up I know how to do that (Main.layoutManager ‘startup-complete’ signal does the trick), but how to do that after resume from sleep or screen lock ?