You aren't alone. I just Googled the topic once again, and found your post. I am also looking for the same mag pouch. I'm tired of dedicating a pocket to a spare double stack .45 mag for my .45acp 4.5" XDm, but I think the options are VERY limited though. I'm continuing to look as well. I have found a couple of options from Safariland and Galco. I'll let you know if I find anything else. Good luck!
XDm 4.5 .45ACP
PX4 9mm Full Size
H&R Pardner Protector 12 Ga.
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