They wouldn't release a BFS assuming current spot I don't think....

They wouldn't release a BFS assuming current spot I don't think. They would need to take the lower market projections. Of course that doesn't mean they can't release a schedule where it shows the NPV at different price levels and allow investors to plug in their own assumptions.
The near term outlook of course is quite difficult to predict and will be affected by political sentiment. For example there is a bipartisan move happening in the US for defence supply https://www.reuters.com/business/energy/exclusive-us-bill-would-block-defense-contractors-using-chinese-rare-earths-2022-01-14/
If this sort of thing spills over to magnets then we could see a spike. However there is also risk of political sentiment impacting the price downwards as has happened in the past. For the long term investor the supply demand story should play out over the next half decade, just have to ride the volatility in the meantime.