Afaik RC only uses the embedded JPG in the RAW, so it should be handled with care. Also, as mentioned, it greatly depends on the windows driver (as Jponathan mentioned) since that is how RC can access RAWs.
How do both of you handle the white balance issue between different cameras? I find that quite challenging to say the least, even though I think RC is doing a great job if the differences stay within limits. BTW, I also use Rawtherapee - despite much criticism, after thorough testing of many different developers I am convinced that it is one of the best. At least for my X-Trans III.
To be honest, I am more and more going back to using JPG directly from the camera. In terms of geometry, the difference is negligible (with quality lenses) despite distortion correction. And if the contrast in the scene isn’t extreme, then there isn’t much need for me to work much with RAW processing, plus it’s a huge time-saver. Cranking up the shadows won’t interfere much with the features in my opinion and it makes a huge difference for alignment.