The European and Chinese companies that market Android e-readers do not have the resources to get access to the source code to upgrade the OS or provide a more robust experience. (goodereader.com)
For a long time, that was the only way to get access to the source. (massivelyop.com)
My current working theory is that this is related to the engine trying to perform some kind of frame pacing, but without access to the source code that is hard to ascertain. (pcgamer.com)