I think that would make sense, yes. Because we use ITK so much for processing we should try to ensure that our image data conforms to its expectations. Hardening seems like the right place to put it.
But probably easiest just to resample into an appropriate right-handed reference grid so not much special code is required.
Actually that reminds me of another issue a student had the other day. She was setting transforms manually that included shears and then hardening them, which works because the volume node can have non-orthonormal directions. But when she saved to nifti and reloaded the images were different (unfortunately in a subtle way) because nifti changes the directions to a quaternion. The workaround was to resample rather than harden.
So I think the code should detect both these cases and resample for hardening or importing.