I have a few things to suggest.

If you get a Doepfer 6u 84HP case, you won't need that 4MS row power module. Also, if you get some of the tiptop 'stackcables,' you won't need to use that multiple module. The only mult modules that do anything past what the tiptop cables do, are buffered multiples which fix issues in 1v/oct tracking of multiple oscillators. However, for a case this small, I don't think that will be an issue, and I wouldn't bother with any multiple modules.

Brains adds a lot of functionality to the pressure points module. Add a sequential switch, and a clock source and the touch module can act as a sequencer.

I would suggest a single quantizer such as the Instruo Harmonaig or ADDAC quad intuitive quantizer. They each have four channels which can be used for CV/gate notes in a chord (which this rack looks like it's trying to accomplish).

Quadra is being replaced by Quadrax and has more functionality. It also has an expander module which allows for more complex envelope patches.

Nothing wrong with that Noise Engineering rhythm generator modules, but you should know where are many other modules which do the same thing. I would research each before choosing one.
That linear mixer is mostly used for CV mixing, and not audio mixing, so you probably want one that does at least exponential mixing. I might suggest the Intellijel quad VCA since it allows you to pick either input curve for each of four channels.

The delay module will just delay 1 cv or audio signal, so if you want a delay for stereo, you would need a different one as well as a stereo mixer (like Happy Nerding Pan Mix).