Except lithium is essentially already nationalised under Chile's current mining code. Lithium is currently deemed as property of the state. We know the current government wants to do away with this antiquated law that was created in the midst of the Cold War, during a time where nuclear weapons were the cause of global panic, but I don't think there is any certainty that they will be able to do so due to not having control of the lower house. If the mining code cannot be altered, then a CEOL will be required, which comes at the decree of the President. Now, I'm certainly no expert on Chilean law and CEOL's, but I would assume if one President can issue a CEOL to a private enterprise, another may take it away. This is where I believe a partnership with Codelco will guarantee protection from any such nonsense, as any President willing to retract a CEOL from a government owned entity would likely face extreme public backlash, and I suspect the reason why we haven't already applied for our own CEOL as of yet despite being formally invited to do so.
Also to be noted that our property rights were not recognised until a few days after Pinera took power. I don't think this was a coincidence in timing. I believe the previous government did not want to recognise our right to exploit lithium from our old code tenements, though would of likely been forced to do so eventually, but not without dragging it out for as long as possible in an attempt to strong arm us in to giving them what they wanted. They made their intentions pretty clear after issuing a CEOL to Codelco covering properties that they do not own.
I don't want to place my faith in any future governments, they may have the intention and capacity to introduce any number of mechanisms that could severely harm our ability to operate if we choose to go at it alone. I see establishing a partnership with Codelco, and thus the government, as our greatest means of protection from any future unknowns.