Indeed, that’s not the case at the moment! It wasn’t in the initial scope of the development.
One option at the moment is to manipulate this value via MQTT from outside Gladys:
MQTT documentation: MQTT API | Gladys Assistant
The feature launch article: Gladys Assistant 4.24 : Envoyer du texte en MQTT / Capteur PM2.5 Zigbee
I’d appreciate it if you could create a feature request 