There is a Catch 22 I see likely throwing a wrench in development from 3rd parties (I could be misreading the market though).
Developing for a device is difficult to justify if the device is not widely used. Installing a chip that doesn’t have a lot of uses is also tougher to justify. In addition, there are folks who are not mentally ready for an implant.
Would a non-implant Spark 2 (or 3) in the form of a wearable possibly expand the number of users, thereby making the services more attractive to develop for?
Counter to my own point - What if you lose your wearable? Is the security risk too much? Could wearables require a pin, but implants not? Would a pin defeat the purpose?
Unrelated: Would love to use my Spark 2 in place of other 2fa systems used in the corporate world. I would pay for that!