The charts are scaled automatically, you don’t really have any control over them.
You have a little more control if you use something like InfluxDB+Grafana to produce your charts, but you still face the problem that OH has no way to provide what amounts to a different sitemap to different devices.
One thing you can do though is use the visibility tag and a Switch with some buttons to manually select and show different versions of the chart. I have an example of this here
The bottom of the top posting on the InfluxDB+Grafana post also has a link to a JS library that lets you dynamically control the chart through webviews, though I’ve had zero success getting webviews to work in Habdroid.