[Bonkers]

If jag had this idea for the F-pace to appeal to a slightly younger market who are tech savvy and lead an active lifestyle, then I can understand the development of the activity bracelet. However, a lot of the people who I see that would fit that profile also seem very keen on other wearable tech (Fitbit etc).
That being the case are they really going to want to wear two such bands? Add in a separate watch (if your other tech doesn't include it) and soon you'll be too weighed down to do anything.
Would have have been a nice idea for them to have developed the AB with it doubling as one of these devices. I am sure it wouldn't have made this option much more expensive and could have increased the uptake

 

[Pos.k]

Nice idea, and that may come, but the issue is two-fold:
1 - The chip in the bracelet / watch is unique and needs to be securely created and assigned to this specific vehicle and associated with this regular key set. This is probably manageable .
The 2nd is that when you sell me your car, I also inherit your sweaty worn every day Fitbit crap covered watch - err no thanks, unless we can swap the security bit to a new device (see 1 above)
Frankly, if Jag looked at this, which I think they may well have, they would probably have said "not our problem".
The real point is that the activity key doesn't have to be in a bracelet _ that is just a convenient enclosure to keep and carry it in.. It could be in a tag or necklace or whatever, but that just complicates their end, the future options will no doubt be more flexible but I'm not sure we're quite there yet!