He said "after that", so I'm presuming he'd try it alone first.
I'm not entirely sure how DiPT would blend with mescaline, but it does seem to shine in combinations, because that allows you to take lower doses. High dose DiPT seems variable based on what I've seen on erowid. There's a certain point where it becomes much more intense and DPT/DMT like, which seems to precipitate panic in some, due to the high degree of mental changes coupled with strong audio hallucinations. DiPT + mescaline could very well be pleasant and add an additional degree of sensory distortion while maintaining the clearheadedness that many find in mescaline.
For some reason, this compound really 'calls out' to me. I'm only somewhat interested in DPT, and otherwise am hoping to try phenethylamines before many tryptamines. How do you think DiPT would be for an inexperienced tripper? I've taken LSD once (hoping for many more doses in the near future) and will also likely be purchasing 2C-E and 2C-D, so I may have some trips with those as well.