Premine: 0.00006%
I found a little mistake here.
Premine = 30000 coins in block #2 that is 0.006%
But it's not a problem. It's still very small premine.
10% of PoW phase, it's huge. Dev cheated

Premine is usually calculated based on Max supply, which is 500 million coins, so the dev is honest in this regard.
Although having 10% of PoW mined blocks does skew coin distribution when the PoS blocks hit... But I think the dev already mentioned in discord there will be airdrops.
