I heard, and read some news that Indonesia did not support crpytocurrency as a currency, but not as an investment tool. well, I also heard that as long as it doesn't interfere with the activities of fiat transactions, that doesn't matter. only the risk is not borne entirely by the state.
That's the point exactly. As long as it doesn't interfere. So if you hold it for "investment purposes" then it is not wrong. It's technically still legal.
Investments can also be used to make transactions from time to time. We cash out of our fixed term deposits to buy houses, pay for education, buy cars, etc. So it really doesn't matter, just keep it and don't tell anyone. Besides, what are they going to do to find out, hack into your email? I doubt it.