Regarding a fingertip install, I can definitely recommend the method my installer used. My finger is large but thin and I haven’t had any issues with rejection. Basically he cut an incision with a scalpel and then used 2 progressively larger tapers, followed by the smallest dermal elevator available from Haworth to create a channel about 1cm deep. Then he just slid it right into the pocket and prodded it deeper with the taper.
You can check out pictures after recovery in this post (you can’t even tell it’s in there), as well as measurements on my finger size.