I wouldn't call Shanzhai open source, its generally much more akin to being where you can obtain documentation on hardware (and the proprietary software stacks

I wouldn't call Shanzhai open source, its generally much more akin to being where you can obtain documentation on hardware (and the proprietary software stacks they run) from the same vendor on the street you bought the device from with no NDAs or other paperwork. There is no way for the end customer to rebuild these blobs and make a blobless Mediatek phone for example, the best your going to get is creativity around the edges, where extra parts and separate bits of software are tacked on after the fact. Honestly, if more of these products shipped with source code, they'd be much easier to secure and extend, but that lesson has yet to come to pass in China.