Attach vapor barrier to the gable / lathing

Hello!

I hope someone can help me here...
The insulation in my roof is now installed everywhere.
Now the vapor barrier and the battens need to go on.
At the gable, the battens would stand about 30cm exposed,
so my question is: Should I drill a batten onto the gable
to be able to fix the battens there again?
And if yes, what is the best way? Stick the vapor barrier to the wall first
or attach a batten first and then install the vapor barrier over it?
Furthermore, I am not sure whether to first put a batten lengthwise
along the rafters, and only then the cross battens (counter battens)
or just do the cross battens and then attach the drywall.

All the material is from Knauf Insulation.
I have the vapor barrier ETA Plus, the adhesive cartridges LDS Solimur,
and the adhesive tapes.

The battens I have are 30x50mm.

Hope someone has an idea.
I also attached a picture.
Best regards, Basti

Hello,

...Furthermore, I am not sure whether to first install battens lengthwise along the rafters, and then the cross battens (cross battens) or simply the cross battens and then the drywall.

First the cross battens, then in the gaps of the new frame add insulation again corresponding to the batten thickness (this smears the thermal bridge "rafter"), then the vapor barrier. Leave about 1.5 to 2 cm overhang at the gable, then bond it afterwards. Cut off protruding edges after the drywall boards.

Best regards.