Unfortunately, scientific names seem to be in a constant state of flux these days, so I find that in my area, I get more “unambiguous precision” by using common names for species. I know of species whose scientific name have changed multiple times within my lifetime, but if I use the common name, everybody knows what I’m talking about.
I’ve found that with some experts, a game of one-upmanship can almost be perceived where it’s a point of pride that one person knows the most up-to-date scientific name for something. I know of one so-called expert who seems to make a point of switching the scientific name he’s using for a particular entity multiple times during the same missive, just to make the point that he has been looking at the entity in question for a long time (or some other obscure point). I go out of my way to use common names when corresponding this this clown just to make it clear that I ain’t impressed, and feel no need to participate in this game. All I want is for the other people participating in a discussion to understand what entity I’m talking about. As I said, I typically find that’s most easily accomplished using common names, but that may not be true when dealing with other taxa.
Oh, and you can coin a common name for something that is not yet officially described (and so, doesn’t have a scientific name yet). I coined a common name for one of our local proto-species, and we’ve been using it extensively now for almost a decade (there was another name, but when it became apparent that this was a real thing, a group of us were discussing alternative names, and the one I came up with ended up sticking). It’s use seems to have spread outside our circle, but because this entity isn’t officially described yet, it’s not on iNat. I expect that when it gets officially described, the common name I coined will be adopted on iNat, because it’s already in use. That seems like a reasonably organic process to me.