Microsoft has recently launched the Portal WEB API in preview. Alot of work those APIs do can be done through connector as well the purpose of launching the API is not a functionality gap but performance improvements.
You can read about the API in the official documentation here. You need to enable site settings to use these API
|Site Setting Name||Description|
|Webapi/<entity name>/enabled||Enables or disables OData API for <entity name>.|
|Webapi/<entity name>/fields||Defines the comma-separated list of attributes that can be modified using Web API.|
– All attributes:
– Specific attributes:
Note: Value should be either * or comma seperated fields name.
Important: Mandatory site setting. When this setting is missing, you’ll see this error: No fields defined for this entity.
|Webapi/error/innererror||Enables or disables innererror.|