I guess you have answered all your initial questions, and that we can keep discussing on the PR directly.
Projecting a scout on the contralateral hemisphere is a question that I got regularly, this can be a useful feature, but the annoying part is that it requires extra parameters when running recon-all.
This must be documented in the FreeSurfer and Scout tutorials for other users to reproduce this:
- https://neuroimage.usc.edu/brainstorm/Tutorials/LabelFreeSurfer
- https://neuroimage.usc.edu/brainstorm/Tutorials/Scouts
The ICBM152 template should be updated as well, and the dataset of the introduction tutorial.
This is not such a trivial change...