Hi!
I'm not sure if this is useful for your particular usage requirements, but have you looked into the Utility Network Trace solutions widget on Github?
https://github.com/Esri/solutions-widget-utility-network-trace
This widget would allow users to run traces on Utility Network services in webapps.
Hey, Alex. I believe I did see that a few weeks back before I posted this message, but at that time I had noticed the tool was 2 years old, so I wrote it off as being incompatible. However I did notice it was updated recently, so I have to assume it was tested on the new UN so I will check it out. Thanks.