MultiCharts: Trading Software for Automated Trading and Backtesting

Maybe it is something special about the video I am using, but I see no difference between SetPlotWidth(1,0); and SetPlotWidth(1,1); in the width of plots. I have to go to SetPlotWidth(1,2); to broaden a line, and I feel I am losing access accordingly to the intermediate thickness.

You are right on this, there's no difference between 0 and 1 widths, use 1-7 values.