You can't really equate the rules that should apply to full democracies with those that should apply to partial democracies or totalitarian regimes.

There's no evidence the US has used NSO like tools to spy on the opposition (post Watergate, anyway).

Partial democracies or totalitarian regimes shouldn't be given these tools under any circumstances since they can't be trusted to only use them to investigate legitimate crimes. They will present some bona fide use scenario, then use the tools for other undisclosed purposes.

If NSO Group had an ounce of ethics, it wouldn't provide the software, but would request a dossier/brief which outlines, with evidence, the basis on which intrusion into the target device is sought. It would then have an agent carry out exploitation. Political "crimes" should be refused service.