When printing AR lowers, below 0.4 mm you get little benefit from improved resolution. Up to 0.6 mm will work, but might require a bit more hand fitting in some areas. I have done the best to design the threads and the rest of the features to work up to 0.6 mm.
The only reason to use a larger nozzle than 0.4 mm is to reduce nozzle clogging with fiber filled materials. I like to use a 0.5 mm as a bit of a compromise.
Unless a design specifies it as OK, I would never use larger then 0.6 mm. Same with small nozzles, unless required by the design, no reason to get smaller then 0.4 mm. The Super Safety and my quad frame are the two projects I have extensively used 0.25 mm nozzles one.
As a final note, there is little evidence to support larger nozzles being stronger, so I would not let that effect the decision.
