I use active dlighting a lot, but when the lighting is very contrasty. your situation wouldnt help because you have consistent lighting in that situation. its not the situation to use adl. just exposure will do the trick.
1 thing I will say regarding nikon cameras (dont know any other) metering and flash metering has not advanced 1 iota since the days of film shooting with F5's (first 1005 3d
color matrix metering) at weddings. not one. they upped the fps, better wb but metering and flash metering in ttl is crap till now. a little backlight or a small light ray comng in the frame and it underexposes. its garbage in every respect.
I never use active dlighting past
normal since it gets a bit too extreme and looks quite bad. if the scene in the shadowed area is patches of light coming in then using adl will help a bit. at least you have the detail in the image so you have a wider dynamic range to edit later.
I dont shoot weddings in raw. but at times when I shoot the groom and bride outdoors I will shoot with adl in harsh situations. like here (sorry for the brutal watermark -had images stolen recently)
here I had a bright white sky and the grass would be underexposed had I metered for that. I shot a few exposures and took one that I could work with. in acdsee pro I lowered the highlights a bit more, upped the shows a bit, then did levels and some contrast to my liking. easy peasey.