If I read that correctly, you are asking about an extra mag pouch attached to the holster (IWB, inside the waist band?), attached by a clip? I don't want to sound preachy/tactical, but if it hits the fan and 7 or 8 rounds dont solve the problem, or there is a malfunction and an immediate action mag change needs to happen, the strong side hand will be occupied with the pistol. Reaching with the weak hand accross the body with the weak hand is unnessary fine moter skill movement. The accepted method is carrying reloads on the weak side. The 1911's, even the alloy frame models are plenty heavy , my vote is for a strong side holster (unless he spends most of his time seated, then crossdraw) with a weakside mag pouch, or mag pouch with a flashlight (always a good gift idea).
When I first started carrying (15ish years ago) I had bought a name brand clip holster/mag pouch combo, no better feeling when practicing drawing from concealment and finding out that that rig was not worth betting your life on. But better finding out that way what works.