But you dont really need to buy your own modem anymore. There’s no issue using spectrums modems. They don’t do anything differently than a store bought one. And there’s no ‘extra’ charge for those. But your own router yes.

In work for them. This is as intended. Its meant to reduce service calls where the customer borks it themselves. I’m not an expert so this may not apply everywhere, but you shouldn’t have a problem using a non-spectrum router without even telling them. I don’t use theirs. You should just be able to go buy it, plug the line in , and turn it on. They don’t need to know. In recommend using your own anyway for many reasons. Yours will be more configurable and you can tell them you don’t need theirs, saving you 7 bucks or whatever a month.