All our dealings with the USCG have been if not pleasant, at least respectful.
They have a job to do, and are efficient and imho have not ever done anything I'd consider a violation of the US Constitution.
We daysail in the path of nuclear submarines coming and going from the Bangor submarine base in Hood
Canal. When they're on the surface, they are surrounded by USCG escorts. Once or twice, we've been shooed out of the way, and I can understand their requirements for space. The machine gun equipped inflatable
which we talked with was very polite, but firm. No problem here.
BTW, the Mexican Navy
boarded us a couple of times while we were in their country.
Their boarding manners were equally good.