First thing I'd check.. side to side play of your front wheel when all mounted up. Possibly needs some adjustment and tightened up on the axle. After that...
You said your disc has a slight wobble. That slight wobble combined with the flexing of "things" while out of the saddle is probably adding up and causing your rubbing. Try to straighten out the disc. Often you can fix a slightly warped disc like that with your hand. Find the area that is out of round, place a clean cloth over that section of the rotor and simply push or pull on the disc with your thumb depending on the wobble direction. The exact pressure depends but you can experiment. A slight rubbing is often just a noise. Yes it is rubbing, yes it is annoying, yes something is not right but a single side slightly scraping a rotor at times is not actually that impactful. It's not near the same as a softer compound rim brake pad further out the wheel rubbing from say a slightly bent wheel. I'd still fix it though.
Another option.. swap front and rear discs. Maybe the current back one is more flat just enough to not scrape. Last resort, maybe your front wheel is "lose", axle is not tight or seated correctly or ill fitting or not clamping correctly and has too much movement.
Last edited by u235; 01-22-20 at 08:50 AM.