I tried doing that. I collected a couple of power cells and then enabled the cheats. I only enabled "Unlimited Arrows" but it somehow gave me "unlimited resources" where resources were not getting depleted. I went into the Ancient Armory cave and triggered the quest. Since I had 2x power cells and had enabled the cheats, I was able to insert ALL FIVE power cells. The game removed the clamps from the armor, and I went to collect it. I did collect it even, as the armor vanished after being collected, but I couldn't find it anywhere in my inventory. When I tracked the quest, it's still stuck at "Collect 3 power cells".
It really sucks that I didn't get the armor
What about you? Did you try with the cheats? Did the same thing happened to you too?
By the way, I'm running HZD Complete Edition with the latest v1.52 patch installed on my PS4 Pro.