Questions about Blake2x: Its state size (internal state) and its security when generating keys with size more than 256/512bits

Question

I read the Blake2x paper: https://www.blake2.net/blake2x.pdf

It says Blake2x can be used to build a "DRBG" (CSPRNG): https://csrc.nist.gov/glossary/term/deterministic_random_bit_generator

"An algorithm that produces a sequence of bits that are uniquely determined from an initial value called a seed. The output of the DRBG “appears” to be random, i.e., the output is statistically indistinguishable from random values. A cryptographic DRBG has the additional property that the output is unpredictable, given that the seed is not known. A DRBG is sometimes also called a Pseudo Random Number Generator (PRNG) or a deterministic random number generator."

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I want to know if the initial state (state size) of Blake2x is "enlarged" when hashing, because I didn't understand this notation:

Despite the internal state of Blake be 256/512 bits, can Blake2x be used to build a stream cipher (CSPRNG/DRBG) with security more than 256/512 bits given a seed with a larger size?

If I have a source full of entropy (like a high resolution photo) and I hash with Blake2x to a key of 8192 bits per example, will I get a key material with this size?

Can some Blake2 enthusiast answer my questions? (I tried to contact one of Blake2x authors, Jean-Philippe Aumasson, but I gave no response).

Why do you care about "more than 256 bit security"? Does your attack model include adversaries that can harness the entire output of the sun to attack your cipher? — poncho, Dec 20 '21 at 15:23
@poncho I want to keep my secrets forever, I hold material about secret societies. — phantomcraft, Dec 20 '21 at 23:06
@kelalaka I want to write a disk encryption program that will use keys sizes like this. — phantomcraft, Dec 20 '21 at 23:07
@kelalaka /\ I already read this topic, but I'm paranoid and I want my secrets safe forever. — phantomcraft, Dec 21 '21 at 01:09
So, how are you going to protect the key? You can't hope to memorize it, and if you store it anywhere, someone could steal it... — poncho, Dec 21 '21 at 01:11
I store the key in a microSD card and hide, if I die, other person who I asked will destroy it. — phantomcraft, Dec 21 '21 at 01:44

Questions about Blake2x: Its state size (internal state) and its security when generating keys with size more than 256/512bits

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