Do any of the Cameras implement a Spring or Elastic like effect when following a target object?
It seems that functionality is missing…
If it is indeed missing, what would be the easiest or most straightforward way to augment an existing cameras with Spring or Elastic behavior?
This thread might be a lot of help New camera position with the animation (transition) to the click of a button
Basically you could animate the camera as you would with other objects 
Also parenting to the object you animate is sometimes a nice way to go.
The forum search is also full of tricks for it : Search results for 'animate camera' - Babylon.js
I am putting it here as you ll be able to find lot of different cases which can provide plenty of ideas hope that helps.
Thanks for the links I will spend some time on that.
Could animating the canvas cause more challenges when enabling WebXR?
I guess if you animate objects not really, but as soon as you animate the camera you might feel deezy… a lot