Optimize (potentially) for reduced CPU usage and thus power consumption.

[BrandonLWhite]

Running the demo page while on battery has a significant impact on my battery life. While there are certainly many factors at play here, I might be able to improve this a bit. The rapidly changing displays are of course the culprit.

• Look for opportunities to avoid altering the SVG and/or DOM.
• Consider a simple numeric backing store value that can be compared to incoming value sets, and guard-clause out if it's the same.