Tomas Slancik

Id assume that if you author asset type primvar then it should be managed like any other asset path in LOPs

If you are authoring it from SOPs you can do that in SOP Import and specify your attrib in Asset Path Attributes instead of keeping it just as string

try unchecking Advanced/Grain Collisions/Assume Uniform Radius

your setup looks good

HypoSection
... I've tried:

v@avoid_force = {1, 0, 0};

But it's still 0, 0, 0 in the geometry spreadsheet.

this would be {0,0,0} only for particles with 0 velocity as there is an early return for those , otherwise you should see {1, 0, 0}

as for

apart from 0 velocity this also depends on f@pscale and whether the particles are actually close enough to impart the avoidforce