I have used Nigari to make tofu and it works great. Can it be used to make non-cultured dairy cheese as well (mozzarella, feta, paneer, etc.)? I looked online and didn't find examples.
Unlike tofu, cheese curds aren't normally precipitated by the addition of salt. They are normally produced by acidification of the milk using a bacterial culture, which grows, producing acids as it does so. The acids then cause the milk solids (proteins) to denature and precipitate.
Salt is often added to the mix at some point, and this can/could help to precipitate the milk solids - in fact you can entirely precipitate milk solids with salt without curdling (this is a process called "salting out" in biochemistry), but this would not make cheese. The salt in cheese is actually added to regulate the types of bacteria that grow in the cheese
You could add the Nigari as the salt content when making cheese (i.e. use it in the place of salt in the recipe, still adding culture) as its very similar to sea-salt (it's produced from sea water after all), and I would be very surprised if no-one has ever used sea salt to make cheese, given that the sea is a pretty handy source of salt for many cultures.
Nigari contains calcium chloride and magnesium chloride, both of which are coagulants used in things like tofu. Calcium chloride is also used for this purpose in cheesemaking.
It would seem like a very salty way of delivering those 2 compounds, but it's not surprising that it works - if you use enough of it - and it's likely that much of the (NaCl) salt ends up in the whey so your final product may not be too salty.