Hi Guys
I've been enjoying using the new Cura and pretty happy with the settings available. I think a feature that would cover what Simon is wanting and many other different scenarios is this though maybe a bit tricky to do the UI for it.
On layer n add this code, do it for n layers, repeat every n layers
Be able to add as many of these lines as you like.
This would enable the user to change fan speed, extrude more or less, increase/decrease nozzle and bed temperature or go faster/slower for different layers.