There's two things that catch my attention here. Other than that, it seems well-rounded. The most-often made mistake with eurorack beginners is a disbalance between audio sources and audio manipulators. You did well on that part.
What I am mostly wondering about is your filter options. You have a LPG (low pass gate) rather than a LPF (low pass filter), a bit of an odd choice. There's videos on Youtube explaining both principles. A module that can do low pass, high pass and band pass filtering will give you more options to play with. But maybe you picked this one on purpose, I'm not familiar with the module and it seems like it can also do normal filtering. Something to think about. If Plaits and Mindphaser are ought to be processed individually, you probably want two filters.
If you really like spring reverb, then go for it. I would not find a great match between Mindphaser and a spring reverb. There's many (cheap or expensive) reverb pedal choices with more flavours of reverb than just springs. I have the Oceans 12 pedal which is the same price as a new assembled Befaco Spring Reverb. Maybe it's overkill for you. EHX Oceans 11 and TC Hall of Fame are cheaper but great options. If you want to keep it in eurorack, the multi-effect unit FX Aid is a popular choice and will give you much more than just reverberation.
One last thing, a passive mult will not copy v/oct melodies. The passiveness will cause a detune to the melody. So you can't mult it to both Mindphaser and Plaits. Maybe there's a solution on the NiftyKeyz, I have no experience with it.