I had good success with a similar keiki just by using sphag and a small pot. It thrived and continued to grow for about 9 months or so until I could pot it in more of small bark mix.

just let it keep growing for a while.. until it has its own roots.... before removing it or anything. make sure you keep water out of the crown.. or it could die of crown rot.. and imagine how inconveniently tiny the next keikis will be. lol

Strictly speaking this is not a keiki. A keiki is a fully formed miniature plant, complete with roots which, in the case of phalaenopsis forms up on the flower stem. This is basal shoot. The distinction is important as unlike a keiki, basal shoots should not be detached from the parent plant.