Hey I have a suggestion about the SP of this account....
Instead of powering it down... can you keep it in this account but delegate it to your own account when the game is over?!
But the only benefit here is to make the SP this account get from one round to the next round (you just have to un-delegate the SP from your account)... I say that so you don't use the power down feature, it makes STEEM value less even if slightly.
I only suggest this in case you didn't think about it and to see if you are okay with it... It means less profit(?) for your main account, so you don't have to take the suggestion.
The main reason I'll be powering down and transferring is I'll be spending some of that money on original art and other things for the game as well as powering up my personal account and helping build the steempower of @steemparents