I've only used Flux Studio to print so far. I mean, I've used Meshmixer and Netfabb to alter or correct models, but only Flux Studio for slicing and printing. I want to try Simplify3D, but haven't got around to it yet.
To clarify, YES, I simply replaced the stock 0.4mm nozzle with the 0.4mm nozzle from the pack you linked to above. You can see the differences in the pictures I posted, but they screw into the heater fine and the 0.4mm nozzle is working great so far.
Once I finish the model I am currently working on, I will attempt to use the 0.2mm nozzle via only changing the nozzle diameter setting in Flux Studio and report back. It likely won't be until tomorrow though.