Is it okay to clone my OS drive instead of doing a clean install?

It's okay to back up copies of important stuff; in fact, you should do it to prevent data loss. Just be cautious about restoring certain folders, especially the Windows folder and any folders with special characters in their names. You should be fine cloning your SSD onto the NVMe; just remember to remove the old SSD after cloning to avoid confusion until you confirm the new installation is working.

There's absolutely nothing wrong with cloning your OS drive to a larger one within the same system. If you're planning to clone it for a new system, that's where it can get tricky due to potential driver issues. Purists will tell you a clean install is better to avoid problems and have a fresh Windows setup, but you can clone successfully too if you know what you're doing.

Cloning isn't bad if done properly, but a clean install is generally safer. For most apps, you can't just copy the AppData folder and expect everything to work. However, for qBittorrent, you can back up 'AppDataLocalqBittorrent' and 'AppDataRoamingqBittorrent' and restore those after you reinstall it. For other programs, you’ll likely need to reinstall them.

Just use Clonezilla to clone your drive. I’ve done it several times without issues.