Switching regulators have their output voltage adjusted via an RSET resistor. The datasheet for the part has a table and a simple equation for figuring out what resistance you need for a given output voltage. They're usually easy to get.
The 63802 can go down to 1v? I thought the min was 1.8v
PTH regs were the standard back in the day because TI used to do cheap sample packs. They also happened to be absurdly reliable. You can use most any switching DC regulator that can handle 3A sustained output. The one you linked looks like it could be passable. No way to know its reliability...
I can confirm that your U10 wire is connected to the wrong via. It should be one via higher as Darkside has said.
The Wii can sometimes boot without the U10 signal. The U10 itself merely takes 3.3v and waits some milliseconds before giving that 3.3v to the CPU as a logic reference signal after...
We had a list of patched emulators that work without all the peripherals somewhere deep in the archives, if it still exists. Otherwise it's a bit of trial and error to find ones that work without the bluetooth module and/or MX chip
If you use Priiloader to manually boot into the homebrew channel then you should be able to install RVLoader to replace the PortabliseMii configuration
Ya so I vastly underestimated the amount of changes I would need to make to even get the printer to the stage where putting a toolchanger in is a viable idea. I have also been repeatedly sick and getting scans and medication and shiz so haven't really been in the mood to do much work on it.
To...
Wiis can just die without rhyme or reason sometimes, but it is odd that both have the same issue. There must be something very specific that isn't immediately visually obvious.
Have you checked that the U10's 3 GND legs have good connection to GND? Sometimes that fails.
Also it is worth probing...