The older version of the API, 1.4, allowed us to download a JSON of the processing rules in a suite. Since these are instrumental in transforming data into eVars, Props, and Events, they are an essential part of maintaining the data quality of a suite. The newest version of the API, 2.0, does not currently support accessing the processing rules, and it's been stated on Github that, as of this idea submission, processing rules access is not even on the roadmap. Unless Adobe is going to eliminate these rules (and the eVars and Props that are driven by them), a mature multi-site installation of Adobe Analytics, esp. across mobile and web, relies on a constant overview of processing rules for maintenance, QA, and to aid site and mobile app developers.
Please make sure that processing rules are accessible via the APIs, not just in version 2.0, but in all future versions. Leaving 1.4 up is not a complete solution, as Adobe may deprecate it at any point.