Ah, maybe that is it. There is a distinction worth diving into between the first project you do as a contractor (where, in my experience, you are hired to deliver) and later projects where you are a known entity who has solved problems and delivered. In the latter case you are (and I have been) able to propose getting up to speed on new technologies.

I was thinking more of the former case when I wrote that, but you're correct, there are different scenarios I glossed over.