Hello,
I cannot tell you if there’s a better way. There are different ways. It sort of depends on your final needs with this camera, I suppose.
If I understand correctly, you want to somehow reproduce the bouncing effect of the arcRotateCamera on the alpha.
‘https://playground.babylonjs.com/#6FBD14#723’
Obviously, you will have to set or keep the upper limit (or use a collision) to stop the camera at your max. Next, again, there are many ways you can bring back the camera to your ‘lower end’ limit (which obviously, you will also need to set or offset from the upper limit). And also many ways you can handle the transition (and in essence, they are all ok if they work and do the job, yes?
So, in my opinion your approach is OK. It’s only for the final bouncing effect you’ll be able to choose from or combine additional functions/parameters such as camera inertia or the camera easing method.