I go with the applique idea. You could even buy a premade applique and just hand stitch it over the spot. Make it easy on yourself.

Thanks to everyone for all the suggestions. I was leaning towards leaving it, and figuring out an applique. Then I started overthinking it, and before I knew it, I had the border partially off, and the new piece on, so I can continue quilting. Now, to satisfy my curiosity, I'm going to sandwich/quit that piece, and run it through a washer cycle and toss it in the dryer. I just need to know if I had I left it alone, would it have come out in the wash!!

If the quilt was for me, after all you tried, I would try to ignore it, but probably would not be able to. Since it is on the border, is it in a location that would tuck into a footboard, or face a wall? Is it in a location where you could put a decorative label on the quilt? Look at the rest of the beauty of the quilt and return to the happy dance!!

You are going to have to tell us what happened when you washed it!

My great granddaughter cut a hole in her quilt right on top of a 3/4" border and into the next border. She also wrote on the quilt with a permanent sharpie.

For the hole, I aplpliqued a heart over the hole and then appliqued a few more scattered around the same border. It worked very well. I'm late answering you so I hope you have already managed it!