IF users are concerned about using an old protocol, then users will need to look into getting in to newer generation NAS. The DNS line is EOL and D-Link is no longer coming out with newer models. Unless there is a major security issue found with DNS, like with the Cryptor problem that D-Link fixed, D-Link is no longer putting out regular FW updates.
I personally have never seen any issues with using SMBv1 ever in all the years of using it. For those that have DNS, NFS is available as an alternative solution for SMBv1 using there DNS if you have concerns about using your DNS.
Good Luck and enjoy.