There seems to be three goals going on here at once:
- Play saxophone through modular tools and effects to alter its sound.
- Play saxophone and have it trigger samples and synth sounds in the rack.
- Play saxophone alongside synths and samples being triggered/played by the rack itself.
If your goal is to do all three of these, I would focus the first row (at least) that you try to put together entirely on goal 1. The Minibrute 2S can cover sounds for now, and I can't imagine you not having another easier way to do samples for now. For now, think about a) getting the sax sound into the modular in a way that sounds acceptable to you and b) modulation. The last one is the main thing missing here: the main reason to do this instead of pedals is the way modulation moves and shapes the sounds in unque ways. I would save extra synth voices and samplers for later and just focus on getting the sax and Minibrute 2S to play together. As for input, also think about emvelope following - turning the amplitude of your sax signal into modulation is a huge part of the potential fun here.
This one has some promising elements. The Barback and Knit are probably unnecessary, but could come in handy for later. Instead, that space might be better served by a Maths, a quad/multi VCA and attenuator, some logic stuff, a mult - the stuff that sounds boring but kind of makes systems workable and flexible. You also may want to look into something to convert modular voltages so they're safe for pedal expression inputs - if you already have pedals, there are many ways to bring them in on the fun here.
I saw you put the Meta-Module in there. Have you tried this concept in VCV Rack yet? Or even with an Empress Zoia or Poly Effects Beebo? Not necessarily as an alternative, but even just as a place to demo patches/module concepts, experiment with them, and potentially cover some ground that would be difficult and expensive in modular (that met. Especially since you'll be busy playing saxophone and not turning knobs as much. I had a Beebo and not only does it have a lot of ports of Mutable Instruments stuff like Plaits, Rings, Marbles (all stuff you have here), but you can use it as a MIDI controller to send Eurorack-style modulations to different MIDI CCs on stuff you may already have.