Welcome!
The sitemap should work with Nuke Platinum. You may have to customize some things - I'm not sure which addon modules it has, but I remember quite a few, and I doubt the sitemap will work with all of them. But that won't stop it from working with the standard ones.
The META tag editor should work, unless Nuke Platinum changed the structure of the includes/meta.php file. Doubt it, but it's possible. It won't hurt to try, as long as you back up your includes/meta.php file...
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