Build an instrument from multiple VSTs

Way back in the day, Opcode’s “Studio Vision” had this great feature. You could select two or more instruments and layer them and save as a new, easy to recall instrument. It would save presets for each and you could assign zones, transpose, crossfades, all kinds of layers, set volume levels etc. I had mega string instruments, cool synth layers, layers and pick and choose drum sets etc

Seems simple enough to do today with VSTs.

Several third-party plugins let you do this.

Bidule by Plogue
PatchWork by Blue Cat
Element by Kushview