Ah, I sailed on hull #007 once that had very large partners.
The reason for using max headstay length is to have more mast rake, which gives more weather helm. If you still need more in under 10 kts, I believe moving the mast butt to the max forward position would help.
Another way to induce weather helm is to heel the boat a bit. Putting some crew weight to leeward would help.
Some people are very good at driving with no feel at all in the tiller. I'm not that good, and prefer a bit of weather helm.
