I also have had some beans that work very well with that time, however, I usually aim for 30ml from a double in a 30 sec pour with the time starting from the first drop comming out (after pre infusion).
I have found some beans (depending on roast profile aswell) that are much better poured with brew temp high (around 96 on the bII) and other beans work better with lower temps (90-92). Generally I start on 96 and move the temp down based on taste.
The brewtus brew boiler has about a 6 degree temp swing, this translates to a 2 degree swing at the head(according to usergroup data) , so I think you really need to make big adjustments (+-3) to really taste the difference. Ill be PIDing mine as soon as warranty is finished.