Is Aurland a reasonable alternative to Flam for 2 nights?
Define "reasonable alternative".
A cute town away from cruise ships.
Supposing you mean Aurlandsvangen which is a small village without own cruise port, so significant less cruise passengers when a ship is in Flåm port, e. g. by bike or bus.
Planning 2 nights there in September- seems like a handy spot for what we want to do; stave churches, walks, and the Sognefjord area.
Maybe if you have a vehicle. It seemed to me it wouldn't work well as a central location using public transport because of limited options.