Add/Remove Worker Icon For Specific Units

Basically I was wondering if there was a way to do this: Give or remove a worker icon for a particular unit group for a specific player. Meaning, it wouldn't work for all the units of type, just the units of type that are owned by player X. The idea is that a player can turn the setting on/off via a toggleable ability.

These units would also change owners, so if player x's units have the setting to have the idle worker icon off, yet player x's settings were set to have the icon show, then the classification of the owner changing units would have to change as well.

I've tried adding/removing unit classification via GUI triggers to make the icon show/be removed; that doesn't work at all.

EDIT: Interesting, seems as if I just have to give the units the worker classification in the object editor, and then remove/give them the classification via triggers... Question solved, for now.

It works? That's cute actually, I remember it being a problem in the past, wonder if this can be abused, hmnn...

Maybe the chaos ability or the blizzard native helped him.