Heya 2070, been a while-ish.

Suggestion: If you do decide to reincarnate BDD with a 5TH/s initial offering, I'd suggest making the B.EXCH market price percentage over the NAV/U increase with the number of excess days of funds in reserve (if there is an excess - otherwise keep it at the fat 2%).  

The reasoning behind this is similar to a point I made a while ago in response to thread members' observations that buyers of B.EXCH who held both the B.MINE and B.SELL shares saw a net yield due to the time series (essentially, in isolation of the capital inflows themselves, "Ponzi"-like) effect of more investors moving capital into the fund after them.  I argued that this was a beneficial effect of the fund's mechanics in that overall it encouraged aggregate net inflows into the fund over time by giving investors an incentive to move capital into the fund sooner rather than later - filling fund reserve deficits more quickly than if this "implied" yield was somehow removed from the fund.

However, when the fund holds an excess of reserves, this means that potential new investors can explicitly buy into a higher-valued pair of units for the same cost.  Granted, this situation would only arise in situations where difficulty periods saw heavy volatility in the forecasted difficulty increase (especially evident with this fund, where some traders use BitcoinWisdom's moving-average-Taylor-Series-like forecasting mdoel), or similarly, when heavy sales of B.EXCH/pair buybacks occurred late in the period (typically past the 10th day).  The circumstances would be rather rare, but still, such a B.EXCH pricing policy should have the effect of further padding the fund NAV/U over fund lifetimes (as well as padding your commission on sales margins, I might add).

Cheers!