If you have 10 bit (10 bits per color per pixel, meaning 30 bits total) processing when 8 bits (8 bits/color/pixel, meaning 24 bits total) are sent, they would perform some type of algorithm in order to scale the 24 bits to 30 bits and to choose a suitable value for the 30 bits. (Or, the processing could be performed from 8 to 10 bits, and the same thing would happen.) I don't think that the bit depth matters much, as 8 bits per color would still give you 16,777,216 (2^24) different color levels. This blocking seems to a function of the machine's processing (including the color wheel) and not any limitation in the bit depth. In other words, upping the bits to 30 won't have a measureable gain.