It has to be possible, though it's admittedly difficult to find it. Here on the Measurement Widget's docs, you can see in the example:
// After creating and adding the DistanceMeasurement2D widget
var measurementWidget = new DistanceMeasurement2D({
view: view
});
view.ui.add(measurementWidget, "top-right");
// Raw measurements (in meters) can be accessed from this property
measurementWidget.watch("viewModel.measurement", function(measurement) {
console.log(
"Length: ", measurement.length,
"Geometry: ", measurement.geometry
);
});
Unfortunately, you can also see in the measurementLabel section:
Lengths are rounded to two decimal places.
So it would seem that to get the raw measurement out and used in place of the label, you're going to have to do more than just change a setting, and get the measurement.length property (an unrounded number of meters) to replace the measurementLabel text somehow.
I'm admittedly out of my depth on the "how" part, but if you can get that raw length number pulled out, I'm sure the rest can't be too difficult. Best of luck!
- Josh Carlson
Kendall County GIS