I will let the code experts speak about code
but as far as welding
MIG and galvinized
NEVER!!!!!!!!!!!!!!!!!
how I was taught and still do it is
SMAW 6012 or 6013
this is just IMHO
sincerely,
Kent
btw: reason for no MIG on galvanized is
spits off metal products
thereby fubaring the mig cup, tip, etc etc

I thought I hand a quick answer for you... Sorry I don't.

The only thing that gives guidance including a measurement after a pretty thorough search provides is for "Repair and Strengthening:   (note the word "galvanized" does not occur in the text)

"8.5.1 Base Metal Condition. Base metal to be repaired
and surfaces of existing base metal in contact with new
base metal shall be cleaned of dirt, rust and other foreign
matter except adherent paint film as per SSPC SP2 (Surface
Preparation Specification #2—Hand Tool Cleaning).
The portions of such surfaces which will be welded
shall be thoroughly cleaned of all foreign matter including
paint for at least 2 in [50 mm] from the root of the
weld."

Having said that (which isn't much yet)   I agree with your desire to qualify a procedure or preferably remove the zinc completely.

D1.1 doesn't much tell you what you can't weld, rather it says that except for certain pre-qualified cases, you have to qualify the welding process / parameters / conditions that you expect before claiming to do work in accordance with the requirements in D1.1.
The latest edition on D1.1 lightened up on surface contaminants, which is a bone of contention...

"5.14.4 Foreign Materials
5.14.4.1 Surfaces to be welded, and surfaces adjacent
to the weld, shall be cleaned to remove excessive quantities
of the following:
(1) Water
(2) Oil
(3) Grease
(4) Other hydrocarbon based materials
Welding on surfaces containing residual amounts of foreign
materials is permitted provided the quality requirements
of this code are met.
5.14.4.2 Welds are permitted to be made on surfaces
with surface protective coatings or anti-spatter compounds,
except those that are prohibited in 5.14.4.1, provided
the quality requirements of this code can be met."

Basically, this means that if you want to weld over zinc, you have to qualify the procedure first.
Qualifying a procedure for hot dip galv is mostly a crap shoot because who knows how thick the zinc will be in the weld areas to be encountered in production, so a procedure qualified under normal conditions may produce bad welds in areas where the zinc is thicker than normal. Bad welds are a liability concern for the contractor, not AWS...
Also, weld fume concerns are also up to the contractor to deal with, not AWS...

I think it's your responsibility to educate yourself and your company about all of the concerns around welding over zinc, before you do so.

That being said, there's a big difference between using Hobart Fabcore F6 to make non-critical welds on galvanealed material, than making moment connections on HDG beams.

I have a copy of the WZC D19.0 - 72. It's full of out dated advice about using different processes on zinc coated material, as well as cracking and safety info. Nothing about procedure qualification.

Tim