Yes the YAMon in question here is a very different beast... it's a tool that provides detailed usage reports on a per device basis.
Sadly, I have only limited experience with LEDE as well...
There are a number of LEDE specific settings which are set in the config scripts... those might require some tweaking. You can find all of the settings in your config.file (typically in /opt/YAMon3/)
Sorry for bumping this topic, but YAMon just got better... There's no LEDE-specific documentation yet, but YAMon is now working on my LEDE router after following the main site's install procedure and the steps on this topic on the forum: