So I got bought some extra nozzles, chucked them up in the lathe sliced them up to make a predetermined nozzle length (in order to "bury" the contact tip with a huge recess) and cobbled together a longer frankenstein nozzle to try out.
Here you can see my standard nozzle (the nickel-plated copper one), and the new mega nozzle. 82.2mm vs 92.5mm. With this setup, I only need 3/8" - 7/16" stand-off distance from the nozzle to the work. First try with only 27CFM of C25 worked great. Close enough to really cut down the shielding gas use, but far enough that it doesn't obstruct the view.
I basically took a cylindrical nozzle, and took off a length, and attached the top of standard conical nozzle so as to have them meet on the flat part and not the taper, and just spot welded it all the way around. Didn't use any filler or anything, just autogenous tacks all the way around. It just needed to not fall off.
Other than the nozzle getting hotter because it is closer to the arc, worked out great for me. I guess if I feel really ambitious I could add water-cooling to the nozzle to wick-out the heat, but that will be a project for another day.
Honestly it would depend on the gun itself, or rather the configuration of the diffuser/nozzle that would ultimately determine if you could shove a custom made gas mesh screen to straighten out the flow. You can only drop the flow so much even with a mesh screen, due to the size [of the opening] of the typical nozzle used for dual shield. I suspect that even with a mesh screen stuck up in there, you won't be able to go much lower than about 23 CFH, since the standard conical nozzle is roughly 5/8" orifice at the nozzle's end, and a conical nozzle is 3/4"-7/8" opening. But then again, there are also smaller MIG guns that use smaller nozzles since they can typically use 0.035" dual shield wire, so those would use even less. My HTP ProPulse 200A MIGs have Euro style MB24KD guns, so those are more suited to 0.035" dual shield. The weld bead I ran was with my MB36KD mig gun that came on my Pro Pulse 300, but I installed it on my Pro Pulse 220MTS since the wire was Lincoln 71M in 0.045" size running at approximately 220A, gun did get a little "toastier" than it normally would, so that is the only downside. Obviously you wouldn't run this on a production type run with high duty cycles.