I remember a post from a few years back in which RC1138 was trying to get karma meshes to work in MP.
When your have a selection in static meshes ie a box you can select to place a KARMA mesh on map .
In it's Properties in HIDDEN there are 2 cells ROLE usually set to AUTHORITY and REMOTE ROLE which I think if set to same ... AUTHORITY should make karma meshes work in MP.
Particle effects if their properties are viewed on a default retail map tend to have the same setting for both cells.
I've not tested it myself yet so any feedback on if this works would be great,
Ive used this same setting for my destructible trap placements from SP on a map for MP .
ROLE and REMOTE ROLE set to AUTHORITY