Having the "Call Alfresco Action" we are able to add and modify aspects of documents stored in Alfesco. I wonder whether the same would be possibile for folders.
Business case: Having a complex long running process we create an Alfesco folder for each process instance. All attachments will be copied to this Alfresco folder. After each process step we update the metadata of this folder using the Store Entity Task, e.g. with a status. I don't want to preset the aspect in Alfresco but add the aspect to the newly created folder initiated by Activiti.
The technical solution behind adding aspect to content or folder is the same, on the ECM side.
From what I understand from your question, you should be able to manage the aspects exactly in the same way. Please let me know if this helps you or I missed some details (in this case, please share them).
As I wrote in my first posting I'm aware of the "Call Alfresco Action" task. You get a couple of functionality to work on documents that are already in Alfresco before the workflow starts. I don't see how to work on a folder that has been created using a Store Entity task. The same seems true for workflow attachments that are copied to Alfresco.
When the "Call Alfresco Action" task is not enough the Script Task can be used, interacting with the Content Services REST API. Using the Content Services REST API you will have the full control of your repository.
To discover the available services you can use the Content Services API-Explorer.