Yes this seems variable based on point of entry. I had (have?) a flagged passport for awhile and I never got the oh shit face from CBP until they scanned my passport.
Curious, why are you flagged? Visited an unsavory country?
Maybe like Tulsi Gabbard they made an enemy of someone in power.
I fought in a US-allied foreign militia against ISIS . So yes.
Is this something you've blogged about or otherwise discussed in more detail?
A college acquaintance of mine ended up in Syria with the YPG and I found it fascinating in a that's-so-fucking-cool-but-I-could-never way.