Taught you well I did, young Jedi...
Locking the Digitakt to the Pam's with the PEXP is a stroke of genius. The ability to not only control your global tempo with one knob, but to even have CV control over that global tempo...you're really going to find a lot of uses for that. As for the Octone, it's a good choice to use with the Sirin...even with Moog's oddball use of negative CVs, the fact is that the positive CVs will be fine. And since the Octone internally quantizes, everything will stay nicely in tune without juggling a bunch of tuning settings at random and inconvenient times. Hopefully. ;)
The setup with the 2hp MIXes is brilliant, too...definitely helps the ergonomics to add those 1 hp blanks, but consider swapping one of those for a Konstant Lab PWR Checker to give you immediate feedback on your power rail loading and voltages. Doesn't get in the way, and it's always useful to have a power indicator for your rails in some place where you can see it in the event something should go bonkers with the power setup.