When running my speaker wires, I ran into an issue with a miscalculation/location of a joist. It was about a 1/2" from the edge of my duct chase. So I attempted to remove the edge trim and drill under it up between joist and inside edge of chase. The angle wasn't enough an I would have drilled right up the middle of the joist, so I had to drill a few inches over at an angle to avoid damaging the integrity of the joist. I debated about removing the rest of the trim and overlaying it with a sheet of veneer, but remembered I had a couple of pieces that were cut out of the side I was putting plate covers over.
I used a hole saw and cut a plug at an angle to match the hole
A little filing I had it fitting, could use a little putty on one side, but I'm happy with the fix, it's pretty un-noticeable.