What differences between v1 and v2 flow actions ?

V2 actions were introduced to simplify how a connection is specified. It uses one string parameter instead of two. This makes it easier to write flows that receive connection as a parameter instead of having it preselected. 

Also, we are in progress of updating how Work Area Connections are handled in relation to new ProjectWise Web Connections releases (to be announced soon). The V2 actions will be updated to display the new connections. 

Flows created with V1 or V2 actions will continue to work, but for all new development I recommend using V2. 

Also, there is one notable difference in V2: actions to create or modify document attributes are different. V1 actions show a control for each attribute in the selected environment. In some cases this list get very long. Also, it was necessary to select an environment to be able to set an attribute. In V2 attributes are accessed as a name-value pair. It means that actions have only necessary controls and also it allows to modify attribute by name (that can even come from variable) without selecting an environment. For example, some configurations have multiple drawing environments tu cater for different document numbering standards. In these environments most of attributes are the same. In V2 it is easier to write a flow that changes, say Title of a document regardless of environment. This was possible in V1, but not as intuitive.  

This topic certainly requires an article from me... 

Thank you for these detailed explanations.

I will test it soon

Is there any difference regarding authentication?
Is there support for logical user access? When defining the connected project connection to the datasource, one can choose to cjeck 'Use IMS  Authentication'. If not checked, can the connector still be used?

Only IMS users are supported by Power Automate connector. The "Use IMS Authentication" option is only used for listing work areas during connection creation, it does not affect the authentication mode for users. 

If you want to use logical account, can I suggest to do not use ProjectWise Connector but the standard HTTP request (require premium power automate licence) and make requests directly to the WSG of your integration server.