One approach could be that SWT chooses the right
thing depending on the OS. That way no client would have to change.
Is there already an enhancement request reported on this topic?
I'm a bit afraid that it becomes a hard a difficult task to do that on the setText of all widgets... I'm also wondering how test frameworks like SWTBot and others who like to look at widget labels would (dis)like it if the actual label can be different from the one that's specified in the code.
Overall, if it's more than a search/replace, the effort becomes IMHO too big for the value it generates.