Looks good. I see three HP of empty space. If you could squeeze in a Poti (3HP) for the Batumi, that would be advantageous. You can change the waveshapes of the Batumi on the fly as well as its behavior regarding sync vs. restarting.
You may also want to check out the micro versions of Clouds and Tides. They'll save you some rack space and give you a little more HP room to play with.
As far as your MIDI to CV converter, you may want to review Expert Sleepers FH2. You'll have more outputs and save some rack space there too.
I don't see any standard envelope generators. You have the Maths and Stages. But you might want something a little more traditional as well like a Tip Top Z4000NS. Each stage of the envelope can be modulated independently as well.
Also, the Erica tube gear uses up a lot of amps when you first turn the system on. Considering that you have a full-boat of modules, CAREFULLY go over the total number of amps you're going to draw per power supply. I believe that you have two.