...it is a 2.3 A max for a 1 MB machine.

There were different shielding configurations in the STe... not all had the PSU screwed to the rear shielding plate.

At the TV, pin 8 has a few kOhms, while blanking input (pin 16) is terminated with 75 Ohm resistor.

Diode and capacitor are needed, because this input has 75 ohm impedance on the TV side, so you can't use 12V out from ST and a resistor divider (actually from the ST you can, but not from STe*), and it needs to be about 2 VDC voltage. VSync obviously is not a DC, and some TVs can switch between comp...

...so maybe you could consider moving abandoned projects to the Public Domain?

Yet, computer should boot just fine, without it.

STe should boot just fine without 12V. STe floppies used in STes don't use it, and even if you'd cut it completely off from the PSU, just the composite video/TV out would be non-functional.

My keyboards also have only one dome under Return key. I think someone had previously "been there", and thought that he had lost one, so he got one extra from eBay, and put it there

Any chances that key caps models will be published on Thingiverse anytime soon? Even as a WIP project?

I didn't mean the time stamps, but completely different fuse map. If you mess too much with the code in editor, and compile just after editing, it is likely, that compiler will output garbage.

Another advantage of Opal Jr is, that it allows to convert JED back to EQN (decompile).