....no problems w/ rubber gaskets or fittings yet.
That's what I was thinking - the casing of some fuel filters are plastic and some fuel lines might be affected over time too. I know a few ounces per tank full isn't much, but acetone can disolve plastics and rubber.
Just for fun, we used to apply some really fine plastic coatings on various items by merely dissolving the plastic cores used in long rolls of film in acetone. Then when the plastic was liquified ( the cores dissolved very fast and we used just enough acetone to cover the core), we dipped our test items into the new plastic/acetone solution and out came a perfectly plastic-coated keepsake. Worked well with most everything we tried. Acetone is a great solvent, but try not to breath its fumes. It also dissolves alveoli and that's not healthy. In concentrated amounts it will dissolve any plastics it finds in a vehicle.