Yes, the 2-step pseudo-code is more or less what I had in mind. It'd be quite laborious to change the API that way, but it could be done. But as you also said, I'm not sure it's worth the effort. And even if I did it with Twitter and Facebook and LinkedIn...it'd be specific to those modules. Any other community-led effort would have to do it, too...in other words, it's not really a Spring Social-specific feature...just a feature of the API binding.
A better approach, in my opinion is this: If you find something missing in the API binding, (1) report it as an improvement issue in JIRA so that I know to attack it (or better yet, submit a pull request along with the JIRA issue)...then (2) in the meantime until it's part of a Spring Social build, call restTemplate() and do the call and binding yourself. Then when it is in a Spring Social build, replace your code with code from the API binding.
Spring Social Project Lead