Please help support the site by donating at the link below.https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=8ZRU34U47BESW
Are you also testing on the PS5? You only mention PC testing, but say they will not detect with the Trigger assemblies plugged in. If all of the assemblies work in another controller, then the SIE would probably be the best guess, as most of the Trigger assembly connections go right to it. Could try reflowing it to see if anything changes first.
The DA9087 is the PMIC, it's full of regulators and such, so I'd expect to see that one warm up a little bit like that. It doesn't look like it's getting too hot from that, unless you've compared it to a fully working one and there's a huge difference? About all it does for the Trigger assemblies is give them power and drive the feedback motors, but if that part of it was an issue it would cause both to not work not just one.