Ok, there exists a fourth export option:

4) PslProject.ExportCloudBundle

But there is also no description or sample code for this option and seems to be not applicable for export via FTP.

Some sample code could be found here: https://docs.rws.com/957276/458889/passolo-automation/pslproject-exporttransbundle. One question that came to my mind was whether the FTP upload is intended to be done within a Collaboration Edition context or if you just want to use the FTP as your repository? 

I wanted to automate export via FTP within Collaboration Edition context.

For FTP export a bunch of settings have to be done in Passolo, e.g., connection name/type, host address/port number. But I couldn't find corresponding method parameters or properties in the COM reference. So it seams it's not possible to do such an export via a macro. 

Ok, Exporting via FTP within the Collaboration context is a one-off action that just needs to be performed once in a project lifetime. This is why these functions and setting are not exposed into the COM object model. Exporting the bundles to a local drive is working, but setting up all data from these dialogs with COM is not possible.

What is possible is to automate the regular synchronization of bundles with the FTP using CLI and COM.