These are the kinds of experiences I'm very curious about (see this thread:
Questions about dreams and daily life, post-breakthrough - Welcome discussion - Welcome to the DMT-Nexus).
I have no personal experience with it, so I can't provide an answer, but I have a gut feeling that the breakthrough "trip" has the potential to act as a catalyst of sorts in our day and night lives.
How long after smoking are you getting these "coming up on DMT" experiences? Hours, days, weeks later? And what do you mean by "coming up on DMT"? What is the feeling/experience?