Okay, Officer, I suppose people should just confess to murder or heroin possession or whatever false accusation you want too, just because “saying no to an officer isn’t the greatest idea”?

No. Sorry if that’s the first time you’ve heard that in a while. But the right to refuse FSTs and the right to refuse to answer questions are so clearly established that there would be no qualified immunity to civil suit if a cop were to arrest someone for refusing.