This could be simplified by allowing raw files as valid inputs for the process "apply montage"
Far from being trivial.
Code suggestions are welcome.
It might also be useful if saved projector files were compatible with montages, i.e. if they could directly be loaded as montages.
Sure. This will not be a priority in my list of developments, but you're welcome to work on it.
note that "Load projectors as montages" should probably be greyed out for imported data files, since it doesn't seem to do anything.
I'm not sure I understand this comment. If the recordings were imported with SSP or ICA projectors applied, you can visualize the ICA/SSP components for these files (even after averaging).