With the caveat that I am using a VC0706 protocol camera very similar to this, but not exactly the same hardware, I have successfully found how to change the baud rate to achieve very reliable and well-tested higher rate. Not only that, but by extrapolating the VC0706 parameters, I run successfully at twice the theoretical limit (of 115200) .... at 230400! This allows the capture of a 640x480 picture in about 5 seconds. See the detail and order of the commands at
https://pixeltwenty.com/tip20182.html as well as the code which govern the careful interaction and timing of retrieving the image. The code was written to transmit the image packets using UDP packets as it goes, where a server reassembles. I also had luck finally finding away to adjust the motion sensitivity as well, shown there too. This code communicates directly with the camera through serial and without using a third party library. Good luck and have fun.