hmm... it should still work.
there are only two places in that plugin that have the customEvalEffect method to process them.
Once in Game_Action (for initiate, select, deselect, conclude, react, confirm, respond, establish)
and once in Game_Battler (for add [includes apply], remove, leave, turn start, turn end, regenerate, action start, action end).
In both methods "user" and "target" are assigned their values.
can you post your notetag?
/Edit:
alright, I did a quick test.
I added the "Fascination" state to a skill and tried to give the actor who uses that skill the "Immortal" state when he applies "Fascination" to an enemy.
"user" gives "Immortal" to the target who gets "Fascination", so you have to use "origin" instead.