So there's actually no real issue, just investors need to be aware if they're going to use the offsite feature (especially if they aren't using it as intended) it can easily backfire and the variance will take them out.
But as always, it's really great people verifying and double checking things. Especially valuable when people like Luxo42 find mistakes, which is something I always appreciate (as honestly, my math skills are a lot weaker than 01010100b's and Luxo42's, I've just been working on this problem domain for quite a while)
maybe the best would be to stop offering the offsite feature for Investors
I don't know about removing that feature - seems useful for those who don't fully trust BaB - lets them limit the risk of BaB absconding with their entire investment. It would seem to create some risk (to the owners of BaB) regarding investors who state large but non-existent off-site holdings