as far as nozzles go iv found using a length of straight brass pipe (1.5mm id on mine) helps
I think it makes the first couple of centimetres of air laminar... better for getting into those deep slots
not a problem if you have an abundance of air like jazz but worth a play if you want to maximise a small compressor

I'm mostly cutting plastics and using a glorified fish tank type pump, the low pressure/volume is not so good for getting jagged alli chips out of narrow slots