Hi James

With the Wersi OAS system, (Still the best interface at making the computer almost totally invisible to the user) you only need to use the Windows interface when first loading the VST instrument software.
Once loaded then everything is done from within the OAS system, (The Wersi VST Host is based on Vstack) and depending on what setups you choose, it can load the plug-ins at start-up, or when you choose a preset.
As an example
Each sound button can store up to 45 different sounds which are selectable from the screen, (These sounds can be internal, external Midi and/or VST etc) consequently you can select any sound from anywhere just as you would an internal sound on a Roland, Yamaha, Korg etc. (If you don’t want to use a main sound button, up to 9 sounds can be loaded per layer per preset)
You can also store the mapping in the preset. (You may not want the same 45 sounds per sound button for all the presets)
The same applies to the accompaniment section, (Operates the same as sounds) and can mix and match Styles, Midi, Video, Wav and Mp3. (Any instrument loaded can be used in the Styles and Midi)

From the information on the Lionstracs site, their version is not as integrated as the Wersi OAS, but compared to using an external computer, (With all the setting up, and cables all over the place) it’s a piece of cake.
Hope this helps put your mind at rest.

Regards

Bill