Are we talking about the same thing? The SMPPS buffer? Which can be negative, and unless you're using a different definition of 'balance' is as likely to be negative as positive?
Yes, and as the creator of SMPPS, I know that the buffer in fact
cannot be negative by definition... Either there are funds in it, or not. There can't be anti-funds in the pool's wallet any more than there can be anti-funds in your own.
OK then. How much does the pool owe its miners then, and what do you call that?