Sorry to kick in with a post, not really answering your main question about integration. But from a musician's point of view, Clinkster is WAY easier to use for non-coders. I'd prefer Clinkster over 4klang anytime.
There's some noteworthy differences between Clinkster and 4klang, though. The main ones are:
1: 4klang supports LFO-control of any given part of the signal-chain, Clinkster doesn't. (resulting in more complex/interesting instruments)
2: 4klang features reverb, Clinkster doesn't (resulting in more complex/interesting instruments)
3: 4klang features filters, Clinkster doesn't (resulting in more complex/interesting instruments)
4: Clinkster doesn't require knowledge of signal processing, 4klang does
5: Clinkster doesn't require knowledge stack based operations, 4klang does
6: Clinkster requires all audio to be precalced, resulting in waiting time before intro starts
7: 4klang is extremely CPU-heavy, making it impossible to compose complex tunes, that require more than 4-5 instruments simultanously
8: Clinkster has a really nice analyzing script, that allows the coder to leave the size-optimizations to the musician.
9: Clinkster usually ends up 2-300 bytes smaller than an equally complex 4klang tunes.
As far as I'm aware, both are somewhat manageble to integrate into your intro, so my suggestion would be to always ask the musician you're cooperating with, which synth he/she prefers, if at all possible. My guess is, that it's easier to find musicians willing to compose using Clinkster than finding someone willing to compose using 4klang.
Hope the above is usefull to somebody

/Punqtured