Yeah, I can see (sort of for the most part) whats going on now - you have 6K coin age total.
The ROI shows you would make -60% ROI on a 2bbp tithe.

Yesterdays contract had about 6B coin*age in it.  So divided by 30 participants you have roughly 200MM or so coin*age going in per participant (roughly, I realize some are much more than others).

What this does is makes it unprofitable to send a tithe unless you have at least about 30,000 ABN weight.  If you had 35K weight you would see something like a 25% or so ROI on the 2bbp tithe.

So, eventually we can put in a break-even output in the exec roi.  And it would be nice to stop the tithe automatically in the miner when it will theoretically result in a loss for the user - that would be real nice also.

I don't have any other suggestions right now other than saving up more coin age.  I can't think of any real world modification to the algorithm other than adding the safeguards etc.  As we already only reward non-sanc free bbp.    If you have any ideas for that please let us know.  I agree, it would be nice to be able to reward the smaller users no matter how low the coin*age is, but that opens up doors for mickey mouse games and squirrely rules etc.  

Simply stopping the tithe until enough age is saved up to surpass a low ROI threshhold would be a pretty good way to fix the lions share of it.