Yes, different circumstances require different approaches to solve.
For example, being a US citizen with a very competent legal team in retainer and the resources to fight a case to the US Supreme Court if necessary my use of GOS with a strong password and (relatively) simple opsec are enough that I have nothing to worry about if US law enforcement (local, state, or federal) seize my phone and I refuse to provide them any information to access it. Law enforcement likely wouldn't even try to compel me to provide access or use that refusal against me because I have the resources to fight the case all the way and they don't want to risk (from their perspective) bad precedent.
Contrast that with an individual in the US on a tourist visa. If you refuse to cooperate then, at a minimum, you will just be kicked out of the US and back to your home country.
Dummy profiles would be nice, but what they won't do is help you against anything but a casual examination.
If law enforcement is looking at your phone then you are already in deep shit. You have already gained law enforcement attention, you have already provided probable cause, and you are essentially already compromised. In spy terms, you are already burned.
GOS might mean you just get booted out of the country instead of doing jail time, or that you are only facing a few years in prison as opposed to life but you have generally already fucked up beyond the point a dummy profile would really help you.
What would be nice is a duress pin feature that would wipe a private space without leaving any forensic evidence that it was there in the first place. Or wipe specific files/folders similarly tracelessly from a profile.
Apparently that isn't actually possible/practical though.