The nozzle diameter is .35, so the plastic extruded through it won't be very much bigger.  You can extrude into air a little bit and measure how wide it is.  At .4, it is almost getting dropped down onto the layer below, fully round rather than squished into it.  If you are trying to save time, you can do taller layers with a .5 nozzle.

Exactly; and isn't it also true there is a optimal layer height for each nozzle hole diameter width due to that effect you spoke of?  I read somewhere that you can't really expect to get the best quality from .10mm small layers from a .35...it's always better to use a different nozzle slightly above the size you want to print vs trying to force under-extrusion or over-extrusion.  You can make the nozzles with brass nuts from McMaster's (I posted the link on here somewhere and you may find that useful)  I used .20 prints on my printer since I read about that extrusion to layer height relation and have had great results, but if I really wanted to push for different layer heights...I would change the nozzle first also.