Here’s my Hank opinion I think might be a little unpopular.
I would’ve gotten rid of the Kryptonite core. Drop that element entirely. If you wanted to do Metallo then you should’ve done Metallo. The reason I would’ve changed it isn’t because he’s not Metallo though. There’s the ever present idea in pop culture that you need Kryptonite to create a real threat for Superman. The end of season one introduced Kryptonite into the world of maws proper fully. Brainiac weaponized Kryptonite during his invasion. Now we had yet another final ish battle with “oh no he has Kryptonite!”. It doesn’t help with the aforementioned idea. Also, of all characters Hank Henshaw simply doesn’t need it. He has all of Superman’s powers plus technopathy. Dude is busted himself. The show actually kept all that too!. The Kryptonite was unnecessary. If you wanted to get rid of his powers Luthor created the parasite tech. It’s right there.