Hello All
Okay, after four weeks of stuffing around with drop particles, workarounds and fudges I can conclusively say - this won't work ! :'(
It seems that even if a particle is tied to an object it doesn't stay with the object, it just takes on the objects position, velocity vector and facing at inception. After that it's on its own.
To make matters worse, the "drop" command returns nothing so you can't assign it and move it along with the person. You could conceivably create particles VERY fast and have them live for a fraction of a second but if the unit moves too fast its "decal" tends to lag behind. This is okay if you want the particle to look randomly uneven but bad otherwise.
On the plus side, if anyone is looking for a spurting blood wound then I'm with sure a few tweaks I could make what you're looking for !
Cheers
Rory