Hi and Welcome to the Community,
Despite your struggle with this camera thingy (cams are sometimes hard to master, don’t ask me 
)…despite of this, I hope you are still enjoying your journey with BJS. Know that the forum will always be here to try give a helping hand and the docs are also constantly improved. Trust me when I say that your/our opinion and feedback really matters here 
The thing is, BJS is a very versatile framework. One of the reasons why I like it so much 
There’s nearly always a couple, a few or more approaches to a problem. I’m not saying, it’s not perfect (yet) Things can still be improved and become more straight-forward and more 'automagical 
)
Let’s take your issue with your arcRotateCamera where you want to ‘freeze’ the cam on pick (and then release it). You choose a way and (applause 
) you managed to make it work. As I often say, the good solution is the solution that works for you. The one you can understand, manage and maintain.
But then, I could give you at least 4 or 5 different ways to obtain the same or very similar result.
Here (below) is one for you, using the angular sensitivity. The good thing with this version is that it does not mess with the inertia and also, likely, angular sensitivity (X and Y on the arcRotateCamera) might be something you want to include in your user settings anyway.
So, I’m not saying this rushed PG of mine is the best solution. Same as your solution is not the best solution. In fact, as I said, the best solution is (in my opinion) the one that works for you.
But (again, my opinion only) we cannot have just all of these solutions in the doc for every topic. Nobody would be able to read the docs anymore. This is why we have the forum and the playground.
I understand that at first it can be a bit hard. You wouldn’t know how much I struggled during my first month (or year) of apprenticeship 
.
But eventually, in a short time, you’ll find that BJS offers some of the best doc and support available on the market. And, if you feel improvements need to be done (and improvements HAVE TO BE DONE), you can also simply post a ‘feature request’ or even simply give your feedback without making a PR. I do it all the time and, incidentally, it looks to me like some of my ‘comments’ ended-up in a PR and have been somehow 'automagically implemented… or am I just dreaming? 