As you probably know, there is one significant difference with regards to ScanSAR SLC products which are delivered in individual bursts on RCM. There are a few other more minor differences (calibration LUT file for each polarization, availability of 32-bit products, etc.).
CSA has a partial dataset of simulated data available here, along with the product format definition:
I wouldn't be the person to write the driver, but would certainly be interested in testing it against our current RCM processing scripts. A GDAL driver could replace a portion of our processing chain down the line, assuming it is able to calibrate all modes, polarization options and product types.