can't, targets are included in the light object itself, don't have the option to merge without the targets. Fortunately I might be done with this scene, however if I have to revisit it then I'll have to rebuild the lighting, which is a huge pain because I work on trade show arch viz stuff and have hundreds of lights in my scenes... I guess thats why they call it alpha ;)
Probably would be a good idea to warn people not to use instanced corona lights w/targets