Streak is 100% built on top of this (source: I work at Streak), so maintaining this is essential to staying in business.

Founder of Streak (author of the InboxSDK) here - and yes we 100% maintain it. We should update the release notes more frequently but we add functionality/fix bugs in the SDK weekly.

So far they haven't and it's been a few years.

The true question is: when is GMail changing its CSS class names ;)