Still no luck with the e-ink panel. I'm sending rand() to the i/o's like someone suggested. Here's what's happening:
- With a constant 3.3V supply, the panel does nothing. That's weird.
- With a 0V or a 3.3V supply through an internal pullup (~47k), the panel shows random lines or columns on power up. And only on power up. I can send anything later and it doesn't do a thing.

Capacitors, capacitors everywhere.
High voltages are super steady, and in the recommended ranges.

Asked the makers of the COGs for complete datasheets, even if the summaries are stating that 2.7 to 3.3V should be fine.

An important thing to note is that I NEVER got areas alone updated. Only either plenty of lines, or plenty of columns. So looking at the equivalent matrix schematic, that would mean that there's only either the source OR the gate voltage at once. I don't see that on the scope, so the mystery remains full :(

Thinking about starting to write the computer software to do something else and to get at least something done. Four days on the same stuff can't be good.