For rough mixes I don't generally use any plug-ins (unless the tracks are poor). Just edit and balance. I see a rough mix as just an opportunity to hear the thing close to how it should be and if it's tracked well it will already be close with nothing. A rough mix is an ephemeral thing by nature so why commit to a signal processor?
But even if you wanted to use processing during the rough stages if you were working analog and sent a "rough" mix to another location you'd have to print at least some of it if you wanted them to hear your mix. It's not like anyone would be expected at a completely different location, with completely different gear, to recall your entire rough analog mix. Why would anything be any different using plug-ins (unless it's a pre-arranged collaboration and you already know they have what you're using)?
__________________ Liz - recordist, mixing dragon lady BLOG some work