Common, guys, why do you think that ALL people arround you are idiots? Why do you think that m0mchil, diablo, jgarzik, puddinpop and others implemented frequent ask rate in their miners? Do you really think that they had not an idea to set it to something longer? They had, but all of them understand that it is bad.  You're reinventing wheel. Wheel with four sides.

You are solving something, what is non-issue. Mining is not about shares/getwork, mining is about shares/time! Moving with ask rate, nobody will search more/less shares per unit of time. And nobody pay more bitcoins to user just because he is more effective from side of "shares/getwork".

You still calculate, that less pool load => more available capacity => more ghash. But nobody is even paid for total pool hashrate, everybody is paid for his shares/total shares. When increasing ask rate, you are lowering your pool load, but increasing probability of stale shares. This mean that every single person have LOWER effective hashrate. He has still 600 Mhash/s on his side with single 5970, but thanks to low ask rate, there are (for example) 5% stale, so user is really adding to the pool only 570 Mhash/s.

Yes, it is with minimal pool load, but he is cutting his income! You have nice tables and graphs, but they display something absolutely irrelevant ; pool users are not interested in your pool load, they are intesteted in their payouts. It's fine that you are running pool with minimal cost and for free, but people pay hidden cost in their lower efficiency (miner efficiency, not pool efficiency).

I'll try to explain that better on one absurd example:
Nonce is number with max value 2^32, it was choosen to be 32bit number by satosthi (probably). But there is no direct relation between nonce range and fact that share with difficulty 1 is one from 2^32 tries; those numbers are choosen artifically. Even better, when I did first version of pool, I could pick one share to be difficulty 2 (2^33 tries) or even more. I choosed difficulty 1 just because I liked that and others adopt my choice. So let's imagine that satoshi had good day and decided that nonce is 2^64. Does that mean that the pool will be the most effective when miners will crunch whole nonce space? Definitely not, because there will be few more blocks sooner than common miner crunch such large space and refresh his job, so majority of his done work was useless. But let's imagine, such ineffectivity! Miners are crunching only few % of 64bit nonce space!

So tell me, please, why are you so much amazed with getwork/share ratio 1:1 ? Do you finally see that there is no reason and it does not improve share rate of anybody?