I have synchronized HighStock charts--multiple y-axes (all logarithmic) sharing the same x-axis. I would like to put plot bands on only the top chart of the synchronized charts.

Is this possible using plot bands?

I came across a StackOverflow answer that recommended plotting area charts on top of the line chart to represent the plot bands. I can do that but the area charts top out at 100% (regardless of how high I set the area chart data), whereas the line chart data goes beyond that.

I could rescale my line chart data to max out at 100%, but then how would I apply the correct y-axis tick labels to the data so that 100% would actually be labeled as the true max value of the data?

I would be incredibly grateful for any suggestions or advice.