I was reminded that someone told me particles can be attached to NPC models. So this tool can now do that, with a drop down of potential attachment points (model bones + attach_to_origin). A model's spell particle attachment points (when they cast or are hit by spells) also seem to be equivalent to weapon particle points, just with special identifying names:
Attaching permanent particles to them works fine ;p
Downside, of course, is that it only works for .eqg-based models, stuff in the 400+ race id range.