I mean the other way....the carbon dosing is what seems superfluous.
Carbon dosing is apparently a stress to corals somewhat (see "burnt tips"), so why do it unless it's completely necessary?*
In general, carbon dosing seems like a self-fulfilling circle of need that starts with a
desire to dose carbon. When the NO3 runs low, why isn't the carbon dosing curtailed and ceased? It's as if someone found an inherent benefit to carbon dosing rather than merely a solution to high nitrates and a new problem called "burnt tips". But they didn't....it was just the latter two.
Most organisms can, at minimum, fix CO2 as a carbon source via carbonic anhydrase...so it seems there's should be no implicit need for this tweak to the system except as a tool for NO3 control. (Someone will also have to explain to me someday why CO2 isn't working in the first place for this.)
Out of control-NO3 is not a lifestyle, it's a solvable problem...or at least it should be. Eh?
2¢
* It's way-cool that we can effect NO3 reduction in the short term with carbon dosing. But based on the "burnt tips" effect and findings like these, I take a different view than most. I characterize vinegar as "the least harmful" carbon source, rather than something with inherent benefits to the system. It's a treatment, if you will.
Vinegar dosing for nitrate control isn't the kind of thing studied directly as far as I can tell (outside of our hobby, anyway) but this is my favorite article on the subject of organic carbon dosing I've found regarding corals so far:
They dose other forms of carbon (sugars) with pretty consistent (bad) results.