Occasionally the court gets political in the sense of avoiding ire and loss of trust from the people so they won't be trying too hard to find reasons to not ban. By their own precedent it's really a slam dunk case, anyway, what I'm saying is that they're very very unlikely to use the opportunity to come up with new requirements.

And really the last time they came up with a new requirement the whole republic had a chuckle. "The NPD is unconstitutional but also politically irrelevant, it shouldn't be banned because it doesn't have any chance of achieving its goals" is humiliating to the Nazis, they can't play martyrs, which is ultimately way more effective.

(The political stuff I'm referring to is e.g. not striking the incest law off the book after their ruling on preventive detention. The detention ruling was legally correct and important, but not very well-recieved because old mistakes meant that certain prisoners couldn't be kept in lockup. The incest law, as-is, can't be defended in a way that either justifies eugenics if applied equally (disabled folks have a greater chance of producing children with genetic defects than 1st generation incest) or is based on "ew, icky", which is no basis for law (but how nature avoids incest). Had the cases been further apart they'd likely have struck the law down, simply saying that the state is free to set out to discourage and prevent incest but criminal law is too harsh a measure).