That's, umm ... nice.
I'm not sure why you bring it up though. I guess because of the product name of the new Logitech trackball.
I had no ulterior motive in bringing it up other than to mention that my choice of mouse is endorsed by my physio.
That's not why I like them, though. Although they do have some ergonomic advantages of their own, shared by all trackball types. Mainly, you don't have to move your wrist at all, unlike any mouse style pointing device.
I haven't tried using a trackball long-term but it seems to me that it would strain my thumb more than a regular mouse would strain my wrist, and that I would have less precision with my thumb. I have a genetic essential tremor that makes my hands less than steady, and I very much doubt that my thumb by itself would have sufficient control of my mouse over three large screens.
But mouses are a very personal thing. What might work for one person might not work for another. You like the trackball. You're entitled to like the trackball. When my WHS assessment was done, one of the options that was offered to me was an
Oyster Mouse. This, by the way, is also the answer to whoever it was asking whether an ergonomic mouse could be configured to use either hand.

I liked the look of it, but I went with the vertical mouse because I've used it before and I know that it works. I probably could have come to enjoy using the Oyster Mouse over time, but given that I won't be in a position to easily swap it out if it doesn't work, I went with what I knew.
I am left handed, and mouse left handed, but I don't reverse the buttons. My preference is a plain mouse, preferably on the small side (allows the hand to rest on it in a non-strained position). The trouble with most "ergonomic" mouses and trackballs is that they are made to be used right handed. Left handed models may be available, but stores don't generally stock them.
In my experience the left-handed versions aren't carried by the big chain stores like Target and Officeworks, but you can always get them from ergonomic office supply stores online, and there exist in a few places
actual brick-and-mortar stores that specialise in ergonomic office equipment. I'm hoping to get myself a new gaming PC after Christmas, and this is where I'll be going to get the mouse and keyboard.