> Do we really assume not being in the US directly fixes everything?

Nobody said anything about fixing everything. When the US fifth amendment doesn’t apply, people have fewer protections from the US government, not more.

Also, I should correct myself slightly on when the US fifth amendment applies: in the rare case where US officials do conduct a custodial interrogation abroad, US courts will recognize the US fifth amendment protection against self-incrimination for statements made to those US officials in that context, even for statements made by foreign nationals. But US courts will not recognize those rights for statements made to foreign officials, outside of two rarely applicable exceptions. Also, of course, dealings within the US with US government officials are constitutionally protected for all nationalities.

I’ve edited my comment upthread accordingly.

With respect to Proton’s home government of Switzerland, they might have more protections or fewer protections than the US fifth amendment offers versus the US government when it does apply - I have no idea and avoided making any assertion either way about that.