With any mead, I recommend that no supplemental acid (of any kind) be added until after the fermentation is complete. And, then add to taste (if needed). IMO, there is no justification to add acid before that point as it serves no purpose other than to tweak the mead's "acid balance" to one's own personal taste.
FWIW, the last time I added any type of acid to a mead was over 10 years ago...
