I think this is a very interesting project, but I don't think this can be calculated so easily.
The thing is, as we know, BTC price against fiat fluctuates very much. If I had, for example, bought shares for 1 BTC when it was worth $10 and gotten 0.5 BTC out of it when 1 BTC was $100, this would technically be a 50% loss, yet it would be almost 400% gain if we take into account the buying power of the returned profits. The same is true the other way around if I invested 1 BTC when the price was $266, and got back 2 BTC when it was worth $100, it would technically be a positive return, but it would still be negative in terms of buying power.
While I agree that the BTC rate should not matter if I bought the shares for BTC, this is simply not the case. Most securities have to convert investors BTC into fiat in order to do something. Therefore, investing into most BTC securities is the equivalent of trading your BTC for fiat and investing said fiat in the company.
For example, if a mining company fails to meet their goals because of a supplier, and wants to get a refund from them to initiate a buy-back in the benefit of their investors, they will still, at most, get back the fiat equivalent of BTC they spent at the moment of spending.
Someday (hopefully soon) upstarts will be able to buy the stuff they need with BTC, and the providers of that stuff will be able to pay in BTC to their suppliers, workers and everyone else. Then the conversion rate will not matter much and, most likely, it will also not fluctuate much. Until that happens, investing into most securities is still basically selling your BTC and investing fiat into the upstart, even if it doesn't seem so.
Don't get me wrong, I'm not saying securities shouldn't strive to be profitable in BTC, as long as they are profitable in fiat. I am just pointing out my opinion that, in the big picture, it is the actual value, or buying power, that matters.