This is actually an awesome feature! Why don't you advertise it more?
I will soon, I just implemented it ( week ago ), it's still under review. I need to know from what amount I will allow to change it, as users who don't have much will lose everything pretty quickly, so at the moment I think about proof of funds for at least 100BTC to allow this change.
That is more or less the way I have imagined implementing something like this myself. You could also keep kelly at 1% for all but base it on a proof of ownership instead of an actual deposit. This is a bit more complicated though. Let's say you demand 10% to be deposited, or 5% or even 1%. The investor would only need to deposit more if his actual deposit reaches zero, or otherwise be auto divested.
Anyway it's great to see some actual innovation for a change. Good luck!