Showing hysteresis state in Curve graphs

[aleksei-suvorov]

First off, huge thanks for this wonderful program!

When configuring my system, I felt what would personally help me understand and "debug" my actions, especially for longer heat saturation optimizations is "where" hysteresis' decision point is.
It acts with the response time I set with a temperature "delay", so it'd help if there was a floating (red or otherwise) dot on the curve that moved as hysteresis moves.

And maybe a (blue or otherwise) dot for the current temperature I am setting. I know the numerical read is at the "source" line, but having a moving dot on the graph would improve legibility of that readout. But that's just nitpicking.