All you are doing is showing that you aren't serious.
> What channel should they use?
Are you f'ing kidding me? You think the federal government doesn't have actual secure channels for discussing sensitive information besides Signal and email? Why don't you just read the f'ing texts, where Mike Waltz specifically references the proper secure channels to use.
> It's not against the law, actually. The President and his cabinet operate on their own rules per the Constitution
Ahh, yes, the new Republican defense of "the law is whatever the President says it is". Actually, no, the executive branch must still follow the law.
And, FWIW, Hegseth and Rubio certainly disagree with you. Just watch their tirades from a few years ago against a previous cabinet member for using unsecured communication channels.
The fact that you are doubling down on "gosh, how can US government security officials have classified conversations besides email or Signal" just shows your ridiculousness. At this point I'd rather have an argument with a dining room table.