I have a TAG slick plate carrier, and I'm looking for something that I can use to easily add or remove the ability to hold some spare AR mags.  To that end, I'm trying to find a kangaroo pouch triple mag insert with full hook coverage on one side and full loop on the other, such that I can put it underneath the two cummerbund flaps when I want it, or easily pull it off when I don't.  

I have a Mayflower triple insert in my spare parts bin, but because it only has a Velcro strip along the top edge, and the rest of the body is very light material, it won't function the way I want it to.  Likewise, most other kangaroo inserts I can find are only Velcro-lined along one edge, or have small patches on the sides, rather than a single large field.  After scouring the internet last night, all I could come up with was some Chinese airsoft pouch that appears to be fully Velcro-lined on both sides, but nothing from any reputable names.  Does anybody make something like this airsoft pouch, that will be of reasonable quality and not ship from Hong Kong?  

This is exactly the kind of pouch I'm looking for, if I can find it from somewhere else.  

SKD has (or had) individual inserts.

TAG sells an insert for their own carriers. Be carefull because the Banshee has a thinner pocket that is no very conducive to holding 3 mags.

Blue Force dapper may work for you too.

I know about SKD's single mag insert for the PIG carrier, but that's not really what I'm looking for.  It's not a full Velcro field, and wouldn't work very well between the cummerbund flaps.  

TAG sells this for the Banshee, but again it's not a full Velcro field like I'm looking for (and it's only 2 mags).  Anyway, I don't have a Banshee, so I'm not worried about the pocket size.  What I have is TAG's slick carrier, like this one.  

I looked at the dapper pouches also, but they appear to be intended for mounting inside a backpack or something similar, and so they only have a Velcro field on one side.

The pic in the OP is really what I need, I'm just hoping I don't have to take a chance with a piece of airsoft gear to get what I'm after.

Well, maybe I'll see how the chinese pouch looks, if it comes back in stock.  If need be, I can reinforce the stitching myself.  

That appears to be the only option for something like this though, unless anybody has a better suggestion.