Red Maple root circling issues (cont'd)

[ChrisWNY]

So I finally got to my Red Maple, a couple of experts on this site recommended I wait until September to correct some Red Maple root circling issues - I posted a thread a few months ago with photos of the issue. To say that the root area was a snake's nest would be an understatement. There were thick roots growing every which direction through the mulch area, I pruned a lot of them so that I could continue to use my garden hose to clear off soil until I got down to the root flare, which was a couple of inches into the soil. At the root flare, there were 2 enormous 3" diameter roots spoking outward the way they should, I had to cut several roots that were growing above these main roots, pressing up against them. A few of the roots were really tight against the trunk, unfortunately I could only get the pruning shears so close without nicking the trunk, so there was some minor tearing of a couple of roots near the trunk, but I was extremely careful NOT to damage the trunk or scratch it in any way.

After the job was done (I didn't take photos because I was more intent on fixing the problem than photographing it), I covered the area back up with a thin layer of cedar mulch. Hopefully this Red Maple will be better off as a result. The trunk/root flare is now exposed and not covered by any soil or mulch. For the couple of roots I tore that were pressed up against the flare on the trunk, do I need to take any measures or will they be ok left alone? I treat this tree every Spring with Bayer Advanced, which contains imadacloprid.