Fluidd "Heaters Off" preset

With Mainsail, the equivalent button command is customizable. It also is in KlipperScreen configuration file.
Didn’t find anything in Fluidd. I’d like to call a custom macro instead of just TURN_OFF_HEATERS (hardcoded in Fluidd ?)

Is it doable ? The documentaion didn’t help.

Of course, I could add a preset. But it is not very clean (two entries instead of one, and the icon doesn’t match the feature) :