Incorrect particle system scaling
Most noticably, this affects the area vfx of certain spells.
#4 Updated by rot tor about 1 month ago
Regarding placing the effects as normal meshes in the game through the construction set and the fact that they don't animate, the same happens in the vanilla engine because they don't have indexed keyframe strings or XNIF/XKF files.
If it's any help with testing some of the files can be found with these added kf strings here: http://tamrielrebuilt.org/asset/vfx-spell-effect-activators