[netcdfgroup] Superblock version 0

Netcdf group,

My team is starting to test netcdf-4.4.1-rc2 with the latest HDF5 library,
currently 1.10.0-patch1.  I see that netcdf-4 files are now being generated
with superblock version 0 for the first time in the history of netcdf-4.
Presumably this is a result of the recent format compatibility fix in 4.4.1.

All the older netcdf-4 files that I sampled, back to the original
netcdf-4.0 (2008), were created as superblock version 2.

Are there any indications whether superblock 0 will be robust and
interoperable, going into the future?

--Dave