Is it possible that they are thinking in the same way as the United States by stamping every Bitcoin block produced in mining pools in Iran with "Made in Iran"? But as far as I know, Iran does not have any large official mining companies or pools, although there are many Iranian citizens who mine.
So I don't know exactly how they will distinguish "Bitcoin produced in Iran"?
White address instead of blacklist.
The same as in South Korea where you need to register and prove to an exchange you won the address to which you're withdrawing the coins, miners could be forced to mine only transactions that are on addresses known to the government and tied to a real person, pretty simple thing, all exchanges will have to comply otherwise they won't be able to receive deposits and from there you have all the databases you need via kyc and deposit/withdrawal data.