Also worried that this ruling doesn't overturn entire part prohibiting criticism of candidates before an election.
It can't, by definition a District Court, nor an Appeals Court, can overturn a Supreme Court decision. They can "work around" it, "reinterpret it", or say it doesn't cover this case (which is what they seem to have done in this instance), but they can't overturn it.
Theoretically even the Supreme Court is not supposed to outright overturn earlier decisions of Constitutional application, at that level, absent a Constitutional Amendment. However they do it as it pleases them.