They mention that they are doing electrochemistry. A huge portion of historical magnesium production is from electrolysis, including the only operating plant in the US. Past methods have used lime to precipitate magnesium (Dow) or evaporation ponds to concentrate it (the current Utah plant). Probably the new thing they are doing is using something like Chlor-Alkali to make base that precipitates the magnesium instead of using lime. Then the electrolysis of molten magnesium salts would be similar to products of today. There is some chance they have improvements in these areas, but there are really only so many options. The job descriptions they've posted support this hypothesis.

Recently most magnesium comes from China. They mine ore, throw it in a coal-fired furnace along with some reducing agents, then collect pure magnesium vapor. This process is more labor and energy intensive, but has significantly less CAPEX. Works for China.

Chlor-alkali is more expensive than lime and the back-end electrolysis is more expensive than thermal reduction. So I'd be skeptical they are going to lower costs without some kind of CAPEX reducing magic for molten salt electrolysis.