Defining labels for thresholds

Hi there, I was wondering if there’s a way to add labels to the thresholds in Time series panels.
Using colours such as green/yellow/red may work on most cases when their implicit meanings are just good/problem/big problem. However, I am developing a dashboard where it can be more nuanced, e.g. one of the thresholds is the design flow. To make meanings as clear as possible to users, I’d like to be able to either add an entry to the panel Legend or to the Tooltip, so that users know exactly what that value is.

Is there a way to do so at present, or anything in the pipeline?

(using v8.0.3)