I would like to have a play and stop button, so you can have the clock stopping or running. Or am i missing something, that its already there.
And is it possible to have internal modulation in a synth? For example, a prepatched (within the synth) LFO that modulates the preset choice (or something else fun like a filter or release, yours to choose)
If you click the yellow hardware menu button that will suspend the entire app. If you mean suspend a particular clock - that’s not available but you can do it with a switch instead.
Lots of synths have params you can hook up to an Oscillator to do what you describle - more customisation will come over the next few months too.