Question about Particle.publish() execution with TTL specified

Hmm, how about this
https://docs.particle.io/reference/device-os/firmware/photon/#particle-publish-

Even if it was implemented, the actual intent of TTL would be the period how long the event will stay valid after it was delivered to the cloud before it vanishes and has nothing to do with the code flow.

Regarding code flow in connection with the publishing it self there are the two flags WITH_ACK and NO_ACK and also this post