The "irony" in supporting that party I believe is a stretch. I don't see how support for some neo-nationalists is inherently "anti-freedom"; would that not apply to any party arguing against open borders?
My personal belief is that professional discrimination because of political support is a very slippery slope, and I honestly think that a lot of people directly or indirectly advocating for it are not fully understanding of what this means and where that slope ends:
When asking about professional boycott for "questionable" past positions (like being gay in Turings time) I only get silence in response because people presumably realize that such witch-hunting often ends up looking really bad in retrospect.
edit: I just misunderstood your last point, completely agree.
It's like people who think Americans shouldn't shouldn't have first amendment rights. The irony is that the first amendment protects their ability to criticize the first amendment.
For better or worse, the internet and all its collective outrage is now the world's HR department.