Tested on EPIC Firmware 2.0. groov View 2.4b.
Works as expected.
The range of the gadget sets the max scale, then the custom markers set the marker value and span.
I did more testing. The marker settings don’t work when “Show Value as” is set to percent. The min max settings are ignored as well - they will always show 0 to 100 - and it is conceivable that someone may want % to display more than 100.