I'm so sorry... It dawned on me this morning, you were asking about using VSTs, VI along side and with your Genos... I guess I was having a senior moment.. I use Logic Pro with a lot of Kontakt, UVI libraries, and a bunch of virtual instruments.
I figure out, and record the left hand chords for Genos in my DAW. sync Genos to follow DAW. Then I mix and match different Genos style parts. Sometimes using Genos, or else Kontakt, or Falcon (which runs UVI libraries).. Sampletank, Musiclab, Rob Papen, Arturia, A.I.R technologies, Superior Drums,Drum-a-gog.
I like using VI's because you can almost instantly bounce them offline, into audio in your DAW.. I will use different instrument parts, from different styles, I will individually overdub just one new style part, while Logic is playing all I previously recorded. The nice thing, is you can switch between your main sections, at different times. so everything doesn't switch at the same time.
I sometime might record four different bass midi styles from Genos. Cut them into one bar chunks, then switch between the four different styles.. You get a bass part, much more complex than from just using a style.. Same with other instruments. One great benefit, is to record a Genos style, then analyze, and learn to play it. It teaches you a lot.
In spite of having to record Genos parts into your DAW in real time. The real beauty as mentioned by Bachus is Genos's real strength are the Articulation , and mega patches. They can really outshine sample libraries in some aspects. I have a few other hardware synths, but mostly stick to virtual instruments and Genos.. It keeps my set-up small.
I have also toyed with creating minor changes in the CHORD track (additional complementary faster changing related chords), in my DAW. I feed this to Genos, for complex kbd, or guitar part.
It takes patience, time. AND it also gives you major insight into creating music.
Another trick, is using Genos Intro's and Outro's with your DAW.. You can tack a different intro onto your song, play the intro blocked CHORD from DAW, you can change key, or chords during a long 8 bar intro. Sounds like you studied 3 years, of music theory, besides sounding stunning and different.
Or you can go as simple as just recording Genos into your Daw, substituting or adding some virtual instruments, to the mix. You can also use some more expensive, reverbs, compressors, mastering plug-ins. I most often substitute Genos drums for Superior drum sounds, or Drum-a-gog or Steven Slates drum replacement system.
It all depends on how involved you want to get with things.
SO, Genos by itself is perfectly excellent, and might be the only tool you need, or you can use any/all of the above or find other techniques.. The beauty of music, is it can provide excitement, joy, regardless of your abilities. Anyone can create and enjoy music, Those of us, who purchase hi end arrangers, have many more tools/techniques at our hands.
I used to own a ton of hardware synths, but bought a Tyros years ago, stripped down my studio, to just a few instruments. I also really did not fair well at playing a Genos live. Moving thru windows, making changes on the fly. I could not remember the sequence of steps to take. So i had to resort using a DAW. I also very much appreciate folks here who can memorize all the had movements to make an interesting piece, live in real time.
Have fun