I’d like to have kind of a container which can contain other midi parts. The idea is to nest midi parts. It could be called sub composition or sub arrangement.
The second request is a CC curve modifier, which is related to the first request, but would also work without it. The idea here is to be able to overlay a curve modifier to alter CC controller data non-destructively in the CC lane. In some cases something similar can already be done using automation but that feels very disconnected to me.
In the picture you can see a curve modifier scaling velocity values.