The titan is a lot higher than quite a few other magnets that are put into fingertips, though I believe it’s about the same size as a silicone haworth. From looking at the install thread, fingertip is still a pretty common location, but a few people have had some issues, or have had to make the pocket bigger than expected. I’m not sure how many of them have rejected, probably 1-2 I think?
The other common sensing position is palm side of P0 (webbing between thumb and index finger). This is actually where I have my titan, and while I find that it’s not quite as convenient from a positioning perspective, I get pretty good sensing (not that I’ve not had a fingertip magnet, so nothing to personally compare to, but a friend of mine had at least 3 titans put in, and found that the fingertip was definitely better at sensing that the palm side P0 one, but more in terms of positioning / clarity IIRC).