ADIT stamp, endorsed immigrant visas, expired GC accompanied by extension letters - all of those carry some degree of risk. The only place that's pretty much guaranteed to recognize these is the US. Airline staff in foreign countries typically doesn't have questions about US passports and valid Green Cards. Everything else is always depends on their training and understanding.
Reddit case proves - the person was admitted to the US even after annoying CBP encounter. Unfortunately this you cannot change. Anybody can be subject to hard time by CBP - from immigrants on visas, to LPRs and even US citizens. It doesn't happen often, but even US citizens can be questioned and detained by CBP when trying to reenter.