Please let me reopen this thread, because I would like to underline the importance of managing sketches.
Dorico is clearly conceived with the goal of producing the most effective final score. That is, with all the individual instruments and sections in the final form.
However, being the powerful composing tool it is, it would be also very useful to have the early stage of writing supported. As discussed above, sketching with a few staves and “general” section sounds is one of the tools most often used by composers. And today we have plenty of sound libraries supporting this way of working.
Currently, Dorico doesn’t support ensemble-type sounds. One can use the Keyboard or Synthesizer instrument definitions to simulate it. I personally use the individual instruments most similar to the ensemble sound I will compose for, and then change the name and reassign the sound.
Supporting custom instrument definitions would probably be the general solution for this and other needs (like supporting the most rare instruments). Maybe playback templates would also be able to link these instrument definitions to a particular sound in a VSTi.
Paolo