Note that this is an old version, I just saw the there's now the "Nome II", and at least for Mac, he has actually developed a USB protocol to provide a stable clock (which as you've already written is totally possible via USB, it's just nobody cared enough):
Thanks a lot!
The scotsman is cool and his t-shirt too. :-D T-Shirt says in German "Little pig".
Regarding "midi notes" Sim'n Tonic himself is saying this to the Midronome:
"Note that only these MIDI messages are simply forwarded when they are received, their timing is not changed. So if your DAW sends them with a lot of latency and/or jitter, the Midronome will forward them with the same latency/jitter. Actually this is a problem I plan on tackling as well [...]"
So the Midronome does not solve the problem of inaccurate midi notes coming from a modern DAW. The USAMO does by the way.. But only with one midi channel at once. And of course, coming back to the actual topic, the Atari hasn't a problem at all with accurate midi notes, it is absolutely tight at all 16 channels. So it seems there is indeed nothing comparable to the Atari nowadays. Maybe it will in the future.
Not sure if that is still accurate. This might only be available for Mac, but on the FAQ for Nome II it says this:
Can Nome II send MIDI Notes?
Nome II is like a MIDI hub, you can ask it to forward any MIDI sent over USB to one of its MIDI outputs. It will not only forward these instantly but merge them smartly with the MIDI Clock, without affecting it.
Here's a review from a nice scotsman explaining how this works:
https://www.youtube.com/watch?v=XCZqkSH9peI
or a walkthrough from the creator:
https://www.youtube.com/watch?v=hkw9dmLfkZQ
Note that this is an old version, I just saw the there's now the "Nome II", and at least for Mac, he has actually developed a USB protocol to provide a stable clock (which as you've already written is totally possible via USB, it's just nobody cared enough):
https://midi.org/innovation-award/u-sync
For Windows, the sync is still done via audio through a special VST.
The YT channel by the creator has many more interesting stuff, he also has done very precise jitter measurements, see for instance:
https://www.youtube.com/watch?v=zGU336yKyEM