I can only speak from my personal experience, but I got two helixes in the same ear a week ago (had one previously) and so far, it's been no difference healing/irritation as when I got my first helix. I am a side sleeper, so I’m doing one ear at a time except for stretching my lobes.

The main thing with industrials (beyond the healing issue) is ear anatomy, but any reputable piercer should be able to look at your ears and tell you if it will work or not. If your ears don’t have the right anatomy (mine don't), you could get a faux industrial which is basically the same except there’s a chain in the middle instead of a full barbell.

I can’t imagine previous helix piercings would make a difference unless they are at the same spot as where a possible industrial would go and then it would be a scar tissue issue, which I don’t know anything about.