R820T I2C

Hi, To teach myself Swift, I’m writing my own version of librtlsdr (in Swift on MacOS). I’m confused about the I2C interface between the RTL2832U and the R820T. It seems the first 16 registers of the R820T can be read but not any after that. I get a pipe stall when trying to read more than 16 bytes. Is this true or am I missing something? Is this why the shadow registers are used to maintain the state of the R820T’s registers? Thanks Chris