@Sylvain @John_Mosher Can you please answer these specific questions?
Advanced parameters are described here:
https://neuroimage.usc.edu/brainstorm/Tutorials/SourceEstimation#Advanced_options:Minimum_norm.5BTODO.5D
Reference articles:
https://neuroimage.usc.edu/brainstorm/Tutorials/SourceEstimation#Additional_documentation