First some special thanks to Kelly Cone for his valuable feedback on areas related to this topic…
Depending on the mass shape you create a curtain system on, Revit may orient the system on some faces opposite in relationship to the neighboring faces. Since you cannot flip a curtain system by face orientation [as you can with a standalone curtain wall] you may need to create a separate system or override the panels \ mullions in this area manually.
You can typically see this variance between curved and straight faces that are part of the same curtain system, for example:
There is one approach, included below, which may allow you to alternate the mass face orientation for some situations.
First, I have embedded a video below, with the larger link as well:
The main item to keep in mind if using the above approach is that any mass floors will also extend out into this portion of mass. While you can set the extrusion of the face to 1/32”, there would technically be a very tiny portion of mass floor in this area; just something to keep in mind.
To recap the process I took:
1. TAB select the flat face portion > Create Form > Pull the front and back faces of the form out.
2. Finish the mass > highlight the curtain system > Edit Face Selection > remove the previous flat face area and add the back of the new form you pulled out. The back of the form should orient the curtain system as desired. Recreate System.
3. Then simply align the back face to match the original face, and you can select the form and manually give the extrusion a Positive Offset such as 1/32”.