Controlling Notch timeline externally

Hello people of Notch!

We are doing a show with live camera inputs to notch that will generate realtime content out via NDI from the notch viewport to a D3 server.

The question i have is how can we control the timeline or switch between layers externally from example the D3, MIDI or Qlab?
We wont be able to export blocks to D3 since its to heavy on the media server.