It doesn’t matter what you are doing. To make a proper comparison, you have to be rigorous. If one processor is doing more or less or different operations, then the comparison is moot. Also, consider how you are using SNR. Statistics are only as good as your methodology and reasons and context for your analysis.
In other words, there is a lot to take into account. Make a table or something of all of the processing steps done by each raw processor you use.
Allow me to give you a tangential example. @Elle, who used to frequent the site, has a website with lots of interesting articles and tutorials. They are dated but look into her comparisons of raw processors. See: Articles and tutorials on Color management. As you can see, you need to be quite thorough.