Hi Felix,
Sorry it's been so long since you got a response, I recently discovered that gmail was putting a bunch of the group mail list messages in my spam directory.
Regarding the flow-chart, I think it should be able to handle that. That said, that part of the library has gone a very long time without getting attention. I can only think of 1 PR that references it in the last few years (there may be more, but I can just recall 1). I don't personally use it myself so I'm not in a good position to explain it one way or the other.
Sorry I can't give anything more definitive.