Personally, I like model number 4 and model number 5.
These two models offer the advantage of having a strong incentive to concentrate around the current price, which eliminates a lot of problems, and that's the whole point.
Of these two models, model 4 really maximises the impact of liquidity in the right place. Capital positioned at the price is really efficient, which is a good thing.
However, REG has a price that moves relatively often compared to the frequency of voting power updates, so I don't know if it's a good idea to have as much capital efficiency as presented in model 4.
Having a wider exponential base is closer to market reality (in terms of the frequency of voting power updates).
So I think I prefer calculation model 5.