Have there been any legal challenges to anti-boycott laws? Freedom of association, or nonassociation, is a core component of freedom of speech. It seems like these laws would be immediately struck down on challenge.

It seems like they're trying to cloud the issue and inappropriately intertwine it with foreign interference laws by not outright prohibiting boycotts of US ally states, but only when they are "encouraged or supported by a foreign state". Just because some country and I both happen to decide to boycott Israel doesn't mean there's any coordination between us or that I just didn't happen to come to the same decision they did independently.