This might be a trade secret, but how are you keeping the colloid solution coherent?

I'm kinda surprised you say that brewing the ristrettos are the hard parts. I know that centrifugal brewing is all the rage these days (as siphon, pour-over, and espresso were before), but it seems like automating espresso is a solved problem. Are there no industrial-scale burr grinders?

I think the biggest problem would be tamping and getting that to be consistent.

Is there anyone who needs industrial scale espresso?