I find this a bit confusing. Montserrat is distributed under an open license [1] which allows commercial redistribution "as long as they [fonts] are not sold by themselves". If people want to use a specific version - and clearly, they feel very strongly about it - why not host it themselves?
Because Google goes out of their way to advise you not to self-host fonts and to use theirs?
Versioning isn't really a huge ask, in my opinion. My experience with Google APIs in general has always been that expectations don't match results. Documentation never matches the specification. This goes double for their own API clients, especially if the language is not Python or Go.
It's sort of maddening how much the company wants you to rely on them for everything and simultaneously not give any concern to how usable their products are.
