I'm not overly concerned ... regardless of the 'fine print' regarding 'listing,' 'classified,' etc.

Good heavens, some clowns are carrying it to the extreme of saying you can't put a classified breaker in an obsolete panel, because, they argue, there is no way the breaker maker could have provided UL with a smaple of that exact panel for evaluation.

Ditto for the various mergers, etc. Again, some folks will say you can't put a Brand X breaker in a panel made by Brad Y, even though the two were once the same firm. You need a scorecard to keep them straight.

Personally, I consider the desires of certain manufacturers to prevent standardising parts to be simply ignorant. "Legal logic" aside, look at every successful product, and you see that it has both opened itself to others, as well as defeated technically better, but proprietary, competitors. VHS/Betamax, Windows/Apple, and Zerk/Alemite are all such examples.

I'd rather see a genuine C-H breaker in a Square-D panel than a counterfeit.

Finally, there are plenty of perfectly legal panels out there that were not made by the guy who made the breakers. A certain -was it Thomas & Betts?' panel comes to mind, as well as the fine panels made by American Switchboard.

What we really need is a way to test breakers for proper operation. Only then could we tell if things are operating properly. If they can invent 'arc detetors,' then a simple overcurrent test ought not be that difficult!