Further research

I realized today that I've never looked at other modchip diagrams. It looks as though most of the points are the same for all chips. Some show the 3.3v and Ground in different places, but that doesn't matter; those are available in multiple spots.

If I ever decided to go with an actual Matrix Infinity, I could just desolder the chip and solder the new one in. That'd be easy. Or solder 2-3 more points for any other modchip.

Makes me wonder why no one just sold PS2s with presoldered wires but no modchip. Leave the "cutting to length" and "soldering to the modchip itself" to the user. I think it would be more appealing, because the points on the chip are larger, you could use any chip you want, and you'd be less likely to damage your PS2. The price could be lowered, and sales would increase for installers.

My two cents.