It also noted it got larger, which it can do whist having a smaller footprint because the iPhone 13 is thicker than the iPhone 12.

If you get a ratio for the volume v weight, you get 159cmm per gram for the iPhone 12 Pro and 138cmm per gram for the iPhone 13 Pro so if anything it has less heavy metals as a ratio of its total volume.

This is a phone where iFixit will have to determine if it's even worth selling replacement parts.

Are there pins on both sides of the Lightning port.

Please x-ray the Lightning to 3.5mm jack adapter so we can see if there's a DAC and AMP built into the cable. Otherwise you're going to have to cut it open, and that won't be pretty.