We are in the process of converting from the SOAP API over to CMIS...
For the most part, everything seems to be do-able, except for issues with the creation of folders and inheritance. It doesn't seem possible to create a sub-folder and NOT inherit the parent permissions.
You also can't disable the inheritance using any CMIS call that I can find...
That is correct. CMIS as an industry standard does not support the Alfresco specific feature of inheritance (dis|en)ablement. This is a use case for hybrid CMIS + ReST API use, which Alfresco recommends as the most suitable approach for integration with Alfresco. Everything that can be done via CMIS will be done that way and the rest (Alfresco specifics) can be mixed in by calling ReST APIs.
Archive: Alfresco Content Services / ECM
Archive content from 2016 and relating to earlier versions of Alfresco Content Services, Community and Alfresco One.