Bassomatic, I am not sure if the quote I have below ties in 100% with the info you provided on Nano One, but let's take a look at one of the statements from your post:

"

• I believe the elimination of metal sulfates is what may be driving LAC to rethink their DFS.  This has to do with their battery production plans which involves sulfates."

OK, an August 2020 article I found had the following statement: 

Geochemistry

Zawadzki said the waste stream of materials remaining after the desired product, in this case lithium, will be extracted and cloistered on a “zero-discharge” facility.

“Geochemistry analysis of the tailing material indicates that the clay tailings do not contain appreciable sulfide sulfur and are unlikely to generate acid from the oxidation of sulfides,” Zawadzki said. “To mitigate against potential impacts, the tailings facility will be constructed as a zero-discharge facility. Tailings material will be filtered, stacked and then stored on lined containment and covered with waste rock/growth media at closure; therefore, no degradation to groundwater is expected to occur.”

Zawadski, of course, refers to Alexi Zawadski, CEO of Lithium Nevada... LAC's subdivision for Thacker Pass.

The bold face italics were provided my me to emphasize that statement by Alexi Zawadski.  The article this comes from is found at:

https://sierranevadaally.org/2020/08/28/thacker-pass-lithium-mine-draft-environmental-impact-statement-reaction/

So, Lithium Nevada is already apparently taking steps to mitigate the effects of sulfur in the tailings, I am presuming this would include "metal sulfates" as well.  Perhaps a future joint operation of some sort with Nano One might further mitigate the  sulfur situation, at least as it applies to any future battery plant operation at Thacker Pass, as it appears that Lithium Nevada is already addressing the situation from the standpoint of processing the lithium clay into lithium carbonate and/or lithium hydroxide.  I hope I am still in the same range here with this observation, although I know your focus in the above is more on the post processing of the lithium clay when and where the proposed battery factory comes into play. 

Regardless of whether we are talking about mitigating the effects of sulfur in the tailings of the mining processing stage or whether we are talking about mitigating effects of the process of making actual lithium batteries at the proposed LAC Thacker Pass battery factory, it does appear that Lithium Nevada and LAC have addressed both of these situations... even more so if Nano One eventually does fit into the same picture frame as does LAC at Thacker Pass. 

Thanks, Bassomatic, for that post!   Okiedo