Active fluxes are generally used for single pass welds and neutral fluxes are often used for multiple pass welds. However, I'm not aware of that as an essential variable in D1.1.
You didn't mention what edition of D1.1 you are using. That may make a difference, but I do not believe it will.
Is this a prequalified WPS? If it is, why is the reviewer looking at Table 4.5 (I'm looking at D1.1-2008)? Clause 4 only comes into play if you are qualifying the WPS because it doesn't meet the requirements for prequalification and it is used as a reference to determine what variables are to be addressed (and their respective ranges) in the WPS. Whether the flux is active or neutral isn't one of the variables listed. If you change to a different F/E combination, a revised prequalified WPS is all that is needed.
The phrase "Pound Sand" comes to mind, but the need to be political correct probably wouldn't allow for such a response.
Best regards - Al