Might be nixxed out of the box due to balance or whatever, but it'd be nice to be able to combine goggles with a balaclava. Whether that'd be by adding a separate goggles-only slot which is available only when wearing a balaclava/other compatible headgear item, or adding a goggles slot to the standard balaclava recipe.
I've also wondered whether it was planned to allow metal helmets to have goggles added in place of the visor slot but that doesn't seem to be happening, and I can understand why.