Having just passed the four week mark, it seems like things aren't going so well. The magnet has slowly moved closer and closer to the surface as the tissue inside heals it out. The same coating that makes the implant biocompatible also makes it quite slick to tissue, which is unable to "grab" it. The surface tissue is completely healed, but pressing gently reveals a spot beneath (it turns white, like when I push on my skin and let go.) In the right light, the dark color of the implant can be seen through the skin.
Gently pushing above the implant reveals that it is quite shallow. The darker area is assumed to be the magnet.The magnet's ability to attract metallic objects has increased dramatically, which also indicates that the implant is getting closer to the surface. This is the critical point though, as the magnet has reached the depth at which the stitch had healed. If the migration stops here, it should be OK. If it continues to push out, however, I will have to remove it. A deeper stitch would be definitely recommended for a later try, as it would cause this critical point to be deeper in the skin as well.
If the implant ends up stabilizing, the migration will be a blessing in disguise. As the magnet has surfaced, my ability to feel minute vibrations has sharpened considerably. For now I will continue letting it be. It is not at all painful or uncomfortable, and still appears to be far enough under the skin to not pose a problem.