IIRC if you don't have enough power for 1 s7 unit when the market for it is removed, it is most likely you won't get anything. I don't remember where i read about that but i think you can find it in their site

you have the option the sell it s7 in market and use that fund to buy new s9 ..

This means that your shares are gone and useless if you have fewer than 4860 GHS.