The simple truth is that you shoudn't consider EMH to be a...

The simple truth is that you shoudn't consider EMH to be a company that will make any big decisions. The mining rights are owned by Geomet, Geomet is 51% owned by Severočeské doly (SD), SD is 100% owned by ČEZ and ČEZ is 70% owned by the ministry of finance and 30% by minority shareholders.

The main decision maker will be the CEO of CEZ which is a political function and has close ties to the government, whether you like it or not. Some weird deals like "we own 49% so we can do whatever we want with 49% of the output" are not possible. There are five directors right now in the BOD:
https://or.justice.cz/ias/ui/rejstrik-firma.vysledky?subjektId=362777&typ=PLATNY
One person from Geomet directly, two persons from ČEZ, one person from EMH and one from Cadence Minerals. The Geomet guy is a former ČEZ employee so if there are any critical decisions, you can imagine who he will side with.

As I already explained what is likely is that there will be an agreement to supply from the daughter company to the parent company - this is exactly how it was done for coal: https://www.cez.cz/cs/pro-investory/informacni-povinnost/uzavreni-smluv-na-dodavky-uhli-v-roce-2007-66656 (both parties are ČEZ and they have an agreement between each other). This is exactly the internal offtake that is planned and ČEZ counts with, do not expect anything less or anything more. It would be much easier if there was some pricing for lithium as a commodity - for example futures on the CME but that doesn't exist yet afaik.