OnePlus 8 Internal Component Testing

Less of a question, but more of a note l guess. I had a badly cracked back screen on my IN2017 model and then accidentally dropped it in water. I immediately removed the back and did my best to dry it. Initially after drying, it seemed to work fine, but after going to sleep it wouldn't power on at all. I ended up buying a cheap refurbished one to swap the motherboard with to confirm it was truly dead, but tested a lot of other things first.

I learned a couple of things:

• I tested the voltage of the battery with a normal multimeter. I could confirm it wasn't dead and it was reading 4.2V
• The loudspeaker/daughterboard cover and motherboard cover can both be removed and the phone will power up fine despite having some contacts on the board. Not sure what they're there for.
• After the motherboard swap, I couldn't get the phone to start with the battery disconnected while plugged into even an "adaptive fast charg[er]," but it did vibrate and try to show the lighting/power icon.
  • That may be a good way to test whether the display is working or not as it also gives the tactile feedback

I'm not sure what the odds are there's someone out there that knows how to "micro-solder" or if it's even possible to remove the "hard drive"/storage and swap them across motherboards, but if anyone knows anything along that line of inquiry that would be super helpful. Thanks!