I listened to a little bit of left-right-center and I think a lot of the arguments against the trucker's that I've heard are really weak because people just keep making arguments against civil disobedience, which they wouldn't make any of those procedural arguments if they thought the cause was noble but that is generally their focus. I'm deeply uncomfortable with the ease with which I hear people make arguments against civil disobedience.
A lot of the first principles in the case aren't even being discussed except by the truckers. I don't think most people are used to actually considering any of these first principles in political debates, because we are so used to saying things like "well you make your choice and I'll make mine" and just agree to disagree.
I don't think it is unique to the truckers, but also the arguments about public school curriculum and censorship where we have issues that require some consensus or a decision about what is the right thing for everyone in society the only people making first principles arguments are people on the right. I don't agree with them, but it is a losing battle to constantly dismiss their first principles and not clash with them on those and instead try to mock or retreat to other more practical or procedural arguments because at some point the first principles should be sorted out and the more open that debate the better.
I kind of disagree to an extent. There is, at times, a fine line between speech and conduct. But free expression can be subject to reasonable time, place, and manner restrictions. The only thing in this whole ordeal I ever cared about was the blocking of the Ambassador Bridge, because a quarter of all trade between the US and Canada flows through that port. That's a real dick move, considering all the issues our economy is already facing (supply chains, inflation, etc.). So, from my perspective, we do not even need to consider the content of the speech in order to condemn the conduct. And I disagree with your supposition that I would feel differently about that if I agreed with the truckers' cause(s). But I probably am looking at this through more of a First Amendment lens than a civil disobedience lens. You may say the foregoing is an argument against civil disobedience, but I simply disagree.
As to first principles: I'm a parent; I haven't got the luxury of principles (jk, just slipping in a quick The Patriot reference). In all seriousness, I am bored and tired of the arguments involved here. It started as a rebuke of Canadian policy as it relates to the vax status of truckers. Then it morphed into an all-encompassing protest against Canadian Covid policies. For one, this isn't really our battle to fight, but to the extent Canadian issues overlap with our domestic ones, I think minds were made up long ago. But also, it's really difficult to pin down exactly which "first principles" are involved, here. You could probably ask 10 different demonstrators who were gathered in Ottawa 10 days ago and receive 10 different answers.