I had a similar problem when using the DB2 chart node, in that the chart line width/style could not be changed, and which therefore did not display higher density data very well.
I worked around that by using the chart.js library in a ui-template node, where I could control the line width to whatever I wanted.
Maybe you could do something similar with a gauge node?
I've since moved to UIbuilder and use justgage, where all options are exposed, and can be tweaked;