Very nice disrupted. I've just begun using this, and while I've been using NirSoft's SmartSniff for packet and traffic analysis (outside of the browser) I find this tool is quite useful as well. I'm able to see things I should be blocking with my hosts file (ads, trackers and widgets) but I also enjoy seeing everything that's been blocked by my hosts file (die ads, trackers and widgets!).
I've found the addon has continued development since your extension was published, though I'm not sure what has changed.
Comparing the contents of the current .xpi and your .7z the structure of things looks very much the same but I haven't yet tried to muddle through making an update myself, for use with KM 1.5.4. Perhaps you could try to make an official update and then be able to say what KM or OS version it might work with or not. Cheers.