Is this just to make it so that the output nc files have different names for each instance? Perhaps we should handle this from inside our IO layer. We should have access to instance details from the driver, so we can simply fwd this to the IO layer (if non-trivial), and add it to the nc file name, like blah[.instance-sha].AVERAGE.ndays_x1.yyyy-mm-dd-xxxxx.nc (where the stuff inside [] is only added if the instance suffix is non-empty).
Originally posted by @bartgol in #7789 (comment)