Hi sorry for the delay.
No minimum of BTC set, so what is sold is sold and what is unsold is unsold and will be burned.
We'll stick to the project and the accorded roadmap anyway. It's understandable that in the event of a low amount of BTC gathered from ICO for development funds, we'll need to use those even more carefully.
So if I read the OP correctly you have 1,200,000 total coin supply for STX.
1,000,000 of them were put on the ICO
200,000 are mineable in the PoW phase next
To date:
roughly 169,000 STX have been sold in the ICO
After the ICO you'll burn the remaining 831,000 STX and there will still be the additional 200,000 STX able to be mined
Giving you a grand total of 369,000 STX before PoS kicks in.
Is that correct?
Your calculations are correct. Final amount of coins depends heavily on the ICO sold coins amount.