Thank you for preparing this video, I hope it will help Muse users to get their data into Brainstorm.
Please note that the source estimation methods you introduced are designed for high-density research EEG caps with electrodes covering the entire head. In your example, the spatial sampling of the scalp potentials is so sparse, there is barely any overlap between the brain signals captured by each of the electrodes, it is not very useful to apply any advanced inverse model.
Processing recordings with Muse headsets should rather focus on extracting features from the EEG signals (eg. computing power in different frequency bands) rather than trying to map this activity on the head.