~snip~
If you are not using any local crypto exchange, I don't think you should be declaring your crypto assets at all. But if you are already using a local exchange, then you data is already available with the government. So if you don't declare, you may receive a tax notice. I will suggest you to speak to a professional tax lawyer to understand the situation in a better way and decide accordingly.
For me I see it as a trap, how would they know how much crypto you hold if you wouldn't even give it to them.
It would be hard for them to track every crypto wallet and impossible to know who owns it, if the owner wouldn't provide any proof of ownership, just like how we still couldn't know who created Bitcoin.
If you look at this situation, you can declare what you have thru your local exchange. Other crypto transactions outside your local exchange may not be compulsory to declare in your tax filing. As they won't know all your crypto transactions, it is none of their business unless, you disclose it to them.