Cameras like the RX100 are a challenge for lens design (read also this). Not sure a fully retractable zoom with 28mm effective WA in such a small body and a 1" sensor can be done without major software lens corrections.
This is an image without any lens corrections (undisclosed 3rd party raw converter used):
This mean we don't just need Raw support for the RX100 but also good lens corrections as well with these raw converters.
The next image shows the JPEG out of the RX100 and the camera performs the needed correction.
To no surprise we get the same corrections from the Sony Image Data Converter because they use the same correction code.
Unfortunately we don't want to use tools like Image Data Converter because they are no match for the top modern raw converters (e.g. Lightroom). We hope that Sony will share this code or lens data with other Raw converters. They should if they want their customers to like the results from the RX100.
Even if we would not get top distortion corrections from other raw converters we could fix some in Lightroom/Camera Raw.
This is the result we get from the first (distorted) photo when we simply apply a manual Lens Transform in Lightroom. Still better than this manual correction would be some more automatic profile based solution.
Todays Raw Converters need to do more than just rendering the pixels. Lens corrections are high on our list.