Regardless of the nitty-gritty “determinism” questions; why’s this matter?

llms are also deterministic

No, in most cases the same input will yield a different output.

No, LLMs are deterministic. What you are describing is a randomized seed, which is another input to the LLM. Some interfaces expose this input, and some do not.

Only if you have a non-zero temperature. You have to program in nondeterminism, because otherwise they are 100% deterministic.

Only because most tools provide a randomize seed alongside the input, but you don't have to do that.

in a deterministic way based on seeds