I tried Etcher with two different SD cards that were formatted first. and got error messages saying the flash operation had not worked, and was left with cards that Windows then could not read or format, and that didn’t boot in the RPi either.
I then reformatted the cards in my digital camera which gave me back cards that Windows could “see” and format again, and tried Win32DiskImager instead of Etcher, with exactly the same image file, and one of the same memory cards that had failed with Etcher. This time everything worked as it should, and Volumio 2 booted, and quickly found ~20k FLAC files stored on a local HDD, and the attached IQaudio DAC, without any settings needing to be changed.
So for me, Etcher didn’t seem to work with either of 2 SD cards, but Win32DiskImager did, and Volumio 2 then just worked straight away, and seems a very worthwhile step up from 1.55.