This isn't a matter of belief or interpretation - it is written clear as day in their ToS and I've pasted all the relevant information in my previous post. I don't want to sound rude but if you need any further confirmation, how about you just go to their website and read their ToS yourself? There is no better source of information on this. After all, Hashnest makes the rules, not some idiots spouting nonsense on a bitcoin forum. Doesn't matter if 9/10 people here tell you you can use your S7 Hash after it's become unprofitable to fund S9s - it's still not going to happen You either have enough hash to redeem for physical machines or your hash is gone forever, buh-bye, investment gone.

In my opinion, if you haven't started mining yet, wait until the S9s are introduced to Hashnest. All it takes is a dip below 620$ / BTC and a day's worth of bad block finding luck and we'll hit 90%+ maintenance, and the S7s will become obsolete. It could happen tomorrow, it could happen in a few weeks. But it'll definitely happen soon, so beware. It's relatively safe to invest again when the S9s are introduced to Hashnest. Provided circumstances don't change dramatically for the worse, they should be profitable for quite some time.